| 1 | /* Cache and manage frames for GDB, the GNU debugger. |
| 2 | |
| 3 | Copyright (C) 1986-2019 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include "defs.h" |
| 21 | #include "frame.h" |
| 22 | #include "target.h" |
| 23 | #include "value.h" |
| 24 | #include "inferior.h" /* for inferior_ptid */ |
| 25 | #include "regcache.h" |
| 26 | #include "user-regs.h" |
| 27 | #include "gdb_obstack.h" |
| 28 | #include "dummy-frame.h" |
| 29 | #include "sentinel-frame.h" |
| 30 | #include "gdbcore.h" |
| 31 | #include "annotate.h" |
| 32 | #include "language.h" |
| 33 | #include "frame-unwind.h" |
| 34 | #include "frame-base.h" |
| 35 | #include "command.h" |
| 36 | #include "gdbcmd.h" |
| 37 | #include "observable.h" |
| 38 | #include "objfiles.h" |
| 39 | #include "gdbthread.h" |
| 40 | #include "block.h" |
| 41 | #include "inline-frame.h" |
| 42 | #include "tracepoint.h" |
| 43 | #include "hashtab.h" |
| 44 | #include "valprint.h" |
| 45 | #include "cli/cli-option.h" |
| 46 | |
| 47 | /* The sentinel frame terminates the innermost end of the frame chain. |
| 48 | If unwound, it returns the information needed to construct an |
| 49 | innermost frame. |
| 50 | |
| 51 | The current frame, which is the innermost frame, can be found at |
| 52 | sentinel_frame->prev. */ |
| 53 | |
| 54 | static struct frame_info *sentinel_frame; |
| 55 | |
| 56 | /* The values behind the global "set backtrace ..." settings. */ |
| 57 | set_backtrace_options user_set_backtrace_options; |
| 58 | |
| 59 | static struct frame_info *get_prev_frame_raw (struct frame_info *this_frame); |
| 60 | static const char *frame_stop_reason_symbol_string (enum unwind_stop_reason reason); |
| 61 | |
| 62 | /* Status of some values cached in the frame_info object. */ |
| 63 | |
| 64 | enum cached_copy_status |
| 65 | { |
| 66 | /* Value is unknown. */ |
| 67 | CC_UNKNOWN, |
| 68 | |
| 69 | /* We have a value. */ |
| 70 | CC_VALUE, |
| 71 | |
| 72 | /* Value was not saved. */ |
| 73 | CC_NOT_SAVED, |
| 74 | |
| 75 | /* Value is unavailable. */ |
| 76 | CC_UNAVAILABLE |
| 77 | }; |
| 78 | |
| 79 | /* We keep a cache of stack frames, each of which is a "struct |
| 80 | frame_info". The innermost one gets allocated (in |
| 81 | wait_for_inferior) each time the inferior stops; sentinel_frame |
| 82 | points to it. Additional frames get allocated (in get_prev_frame) |
| 83 | as needed, and are chained through the next and prev fields. Any |
| 84 | time that the frame cache becomes invalid (most notably when we |
| 85 | execute something, but also if we change how we interpret the |
| 86 | frames (e.g. "set heuristic-fence-post" in mips-tdep.c, or anything |
| 87 | which reads new symbols)), we should call reinit_frame_cache. */ |
| 88 | |
| 89 | struct frame_info |
| 90 | { |
| 91 | /* Level of this frame. The inner-most (youngest) frame is at level |
| 92 | 0. As you move towards the outer-most (oldest) frame, the level |
| 93 | increases. This is a cached value. It could just as easily be |
| 94 | computed by counting back from the selected frame to the inner |
| 95 | most frame. */ |
| 96 | /* NOTE: cagney/2002-04-05: Perhaps a level of ``-1'' should be |
| 97 | reserved to indicate a bogus frame - one that has been created |
| 98 | just to keep GDB happy (GDB always needs a frame). For the |
| 99 | moment leave this as speculation. */ |
| 100 | int level; |
| 101 | |
| 102 | /* The frame's program space. */ |
| 103 | struct program_space *pspace; |
| 104 | |
| 105 | /* The frame's address space. */ |
| 106 | const address_space *aspace; |
| 107 | |
| 108 | /* The frame's low-level unwinder and corresponding cache. The |
| 109 | low-level unwinder is responsible for unwinding register values |
| 110 | for the previous frame. The low-level unwind methods are |
| 111 | selected based on the presence, or otherwise, of register unwind |
| 112 | information such as CFI. */ |
| 113 | void *prologue_cache; |
| 114 | const struct frame_unwind *unwind; |
| 115 | |
| 116 | /* Cached copy of the previous frame's architecture. */ |
| 117 | struct |
| 118 | { |
| 119 | int p; |
| 120 | struct gdbarch *arch; |
| 121 | } prev_arch; |
| 122 | |
| 123 | /* Cached copy of the previous frame's resume address. */ |
| 124 | struct { |
| 125 | enum cached_copy_status status; |
| 126 | CORE_ADDR value; |
| 127 | } prev_pc; |
| 128 | |
| 129 | /* Cached copy of the previous frame's function address. */ |
| 130 | struct |
| 131 | { |
| 132 | CORE_ADDR addr; |
| 133 | int p; |
| 134 | } prev_func; |
| 135 | |
| 136 | /* This frame's ID. */ |
| 137 | struct |
| 138 | { |
| 139 | int p; |
| 140 | struct frame_id value; |
| 141 | } this_id; |
| 142 | |
| 143 | /* The frame's high-level base methods, and corresponding cache. |
| 144 | The high level base methods are selected based on the frame's |
| 145 | debug info. */ |
| 146 | const struct frame_base *base; |
| 147 | void *base_cache; |
| 148 | |
| 149 | /* Pointers to the next (down, inner, younger) and previous (up, |
| 150 | outer, older) frame_info's in the frame cache. */ |
| 151 | struct frame_info *next; /* down, inner, younger */ |
| 152 | int prev_p; |
| 153 | struct frame_info *prev; /* up, outer, older */ |
| 154 | |
| 155 | /* The reason why we could not set PREV, or UNWIND_NO_REASON if we |
| 156 | could. Only valid when PREV_P is set. */ |
| 157 | enum unwind_stop_reason stop_reason; |
| 158 | |
| 159 | /* A frame specific string describing the STOP_REASON in more detail. |
| 160 | Only valid when PREV_P is set, but even then may still be NULL. */ |
| 161 | const char *stop_string; |
| 162 | }; |
| 163 | |
| 164 | /* A frame stash used to speed up frame lookups. Create a hash table |
| 165 | to stash frames previously accessed from the frame cache for |
| 166 | quicker subsequent retrieval. The hash table is emptied whenever |
| 167 | the frame cache is invalidated. */ |
| 168 | |
| 169 | static htab_t frame_stash; |
| 170 | |
| 171 | /* Internal function to calculate a hash from the frame_id addresses, |
| 172 | using as many valid addresses as possible. Frames below level 0 |
| 173 | are not stored in the hash table. */ |
| 174 | |
| 175 | static hashval_t |
| 176 | frame_addr_hash (const void *ap) |
| 177 | { |
| 178 | const struct frame_info *frame = (const struct frame_info *) ap; |
| 179 | const struct frame_id f_id = frame->this_id.value; |
| 180 | hashval_t hash = 0; |
| 181 | |
| 182 | gdb_assert (f_id.stack_status != FID_STACK_INVALID |
| 183 | || f_id.code_addr_p |
| 184 | || f_id.special_addr_p); |
| 185 | |
| 186 | if (f_id.stack_status == FID_STACK_VALID) |
| 187 | hash = iterative_hash (&f_id.stack_addr, |
| 188 | sizeof (f_id.stack_addr), hash); |
| 189 | if (f_id.code_addr_p) |
| 190 | hash = iterative_hash (&f_id.code_addr, |
| 191 | sizeof (f_id.code_addr), hash); |
| 192 | if (f_id.special_addr_p) |
| 193 | hash = iterative_hash (&f_id.special_addr, |
| 194 | sizeof (f_id.special_addr), hash); |
| 195 | |
| 196 | return hash; |
| 197 | } |
| 198 | |
| 199 | /* Internal equality function for the hash table. This function |
| 200 | defers equality operations to frame_id_eq. */ |
| 201 | |
| 202 | static int |
| 203 | frame_addr_hash_eq (const void *a, const void *b) |
| 204 | { |
| 205 | const struct frame_info *f_entry = (const struct frame_info *) a; |
| 206 | const struct frame_info *f_element = (const struct frame_info *) b; |
| 207 | |
| 208 | return frame_id_eq (f_entry->this_id.value, |
| 209 | f_element->this_id.value); |
| 210 | } |
| 211 | |
| 212 | /* Internal function to create the frame_stash hash table. 100 seems |
| 213 | to be a good compromise to start the hash table at. */ |
| 214 | |
| 215 | static void |
| 216 | frame_stash_create (void) |
| 217 | { |
| 218 | frame_stash = htab_create (100, |
| 219 | frame_addr_hash, |
| 220 | frame_addr_hash_eq, |
| 221 | NULL); |
| 222 | } |
| 223 | |
| 224 | /* Internal function to add a frame to the frame_stash hash table. |
| 225 | Returns false if a frame with the same ID was already stashed, true |
| 226 | otherwise. */ |
| 227 | |
| 228 | static int |
| 229 | frame_stash_add (struct frame_info *frame) |
| 230 | { |
| 231 | struct frame_info **slot; |
| 232 | |
| 233 | /* Do not try to stash the sentinel frame. */ |
| 234 | gdb_assert (frame->level >= 0); |
| 235 | |
| 236 | slot = (struct frame_info **) htab_find_slot (frame_stash, |
| 237 | frame, |
| 238 | INSERT); |
| 239 | |
| 240 | /* If we already have a frame in the stack with the same id, we |
| 241 | either have a stack cycle (corrupted stack?), or some bug |
| 242 | elsewhere in GDB. In any case, ignore the duplicate and return |
| 243 | an indication to the caller. */ |
| 244 | if (*slot != NULL) |
| 245 | return 0; |
| 246 | |
| 247 | *slot = frame; |
| 248 | return 1; |
| 249 | } |
| 250 | |
| 251 | /* Internal function to search the frame stash for an entry with the |
| 252 | given frame ID. If found, return that frame. Otherwise return |
| 253 | NULL. */ |
| 254 | |
| 255 | static struct frame_info * |
| 256 | frame_stash_find (struct frame_id id) |
| 257 | { |
| 258 | struct frame_info dummy; |
| 259 | struct frame_info *frame; |
| 260 | |
| 261 | dummy.this_id.value = id; |
| 262 | frame = (struct frame_info *) htab_find (frame_stash, &dummy); |
| 263 | return frame; |
| 264 | } |
| 265 | |
| 266 | /* Internal function to invalidate the frame stash by removing all |
| 267 | entries in it. This only occurs when the frame cache is |
| 268 | invalidated. */ |
| 269 | |
| 270 | static void |
| 271 | frame_stash_invalidate (void) |
| 272 | { |
| 273 | htab_empty (frame_stash); |
| 274 | } |
| 275 | |
| 276 | /* See frame.h */ |
| 277 | scoped_restore_selected_frame::scoped_restore_selected_frame () |
| 278 | { |
| 279 | m_fid = get_frame_id (get_selected_frame (NULL)); |
| 280 | } |
| 281 | |
| 282 | /* See frame.h */ |
| 283 | scoped_restore_selected_frame::~scoped_restore_selected_frame () |
| 284 | { |
| 285 | frame_info *frame = frame_find_by_id (m_fid); |
| 286 | if (frame == NULL) |
| 287 | warning (_("Unable to restore previously selected frame.")); |
| 288 | else |
| 289 | select_frame (frame); |
| 290 | } |
| 291 | |
| 292 | /* Flag to control debugging. */ |
| 293 | |
| 294 | unsigned int frame_debug; |
| 295 | static void |
| 296 | show_frame_debug (struct ui_file *file, int from_tty, |
| 297 | struct cmd_list_element *c, const char *value) |
| 298 | { |
| 299 | fprintf_filtered (file, _("Frame debugging is %s.\n"), value); |
| 300 | } |
| 301 | |
| 302 | /* Implementation of "show backtrace past-main". */ |
| 303 | |
| 304 | static void |
| 305 | show_backtrace_past_main (struct ui_file *file, int from_tty, |
| 306 | struct cmd_list_element *c, const char *value) |
| 307 | { |
| 308 | fprintf_filtered (file, |
| 309 | _("Whether backtraces should " |
| 310 | "continue past \"main\" is %s.\n"), |
| 311 | value); |
| 312 | } |
| 313 | |
| 314 | /* Implementation of "show backtrace past-entry". */ |
| 315 | |
| 316 | static void |
| 317 | show_backtrace_past_entry (struct ui_file *file, int from_tty, |
| 318 | struct cmd_list_element *c, const char *value) |
| 319 | { |
| 320 | fprintf_filtered (file, _("Whether backtraces should continue past the " |
| 321 | "entry point of a program is %s.\n"), |
| 322 | value); |
| 323 | } |
| 324 | |
| 325 | /* Implementation of "show backtrace limit". */ |
| 326 | |
| 327 | static void |
| 328 | show_backtrace_limit (struct ui_file *file, int from_tty, |
| 329 | struct cmd_list_element *c, const char *value) |
| 330 | { |
| 331 | fprintf_filtered (file, |
| 332 | _("An upper bound on the number " |
| 333 | "of backtrace levels is %s.\n"), |
| 334 | value); |
| 335 | } |
| 336 | |
| 337 | |
| 338 | static void |
| 339 | fprint_field (struct ui_file *file, const char *name, int p, CORE_ADDR addr) |
| 340 | { |
| 341 | if (p) |
| 342 | fprintf_unfiltered (file, "%s=%s", name, hex_string (addr)); |
| 343 | else |
| 344 | fprintf_unfiltered (file, "!%s", name); |
| 345 | } |
| 346 | |
| 347 | void |
| 348 | fprint_frame_id (struct ui_file *file, struct frame_id id) |
| 349 | { |
| 350 | fprintf_unfiltered (file, "{"); |
| 351 | |
| 352 | if (id.stack_status == FID_STACK_INVALID) |
| 353 | fprintf_unfiltered (file, "!stack"); |
| 354 | else if (id.stack_status == FID_STACK_UNAVAILABLE) |
| 355 | fprintf_unfiltered (file, "stack=<unavailable>"); |
| 356 | else if (id.stack_status == FID_STACK_SENTINEL) |
| 357 | fprintf_unfiltered (file, "stack=<sentinel>"); |
| 358 | else |
| 359 | fprintf_unfiltered (file, "stack=%s", hex_string (id.stack_addr)); |
| 360 | fprintf_unfiltered (file, ","); |
| 361 | |
| 362 | fprint_field (file, "code", id.code_addr_p, id.code_addr); |
| 363 | fprintf_unfiltered (file, ","); |
| 364 | |
| 365 | fprint_field (file, "special", id.special_addr_p, id.special_addr); |
| 366 | |
| 367 | if (id.artificial_depth) |
| 368 | fprintf_unfiltered (file, ",artificial=%d", id.artificial_depth); |
| 369 | |
| 370 | fprintf_unfiltered (file, "}"); |
| 371 | } |
| 372 | |
| 373 | static void |
| 374 | fprint_frame_type (struct ui_file *file, enum frame_type type) |
| 375 | { |
| 376 | switch (type) |
| 377 | { |
| 378 | case NORMAL_FRAME: |
| 379 | fprintf_unfiltered (file, "NORMAL_FRAME"); |
| 380 | return; |
| 381 | case DUMMY_FRAME: |
| 382 | fprintf_unfiltered (file, "DUMMY_FRAME"); |
| 383 | return; |
| 384 | case INLINE_FRAME: |
| 385 | fprintf_unfiltered (file, "INLINE_FRAME"); |
| 386 | return; |
| 387 | case TAILCALL_FRAME: |
| 388 | fprintf_unfiltered (file, "TAILCALL_FRAME"); |
| 389 | return; |
| 390 | case SIGTRAMP_FRAME: |
| 391 | fprintf_unfiltered (file, "SIGTRAMP_FRAME"); |
| 392 | return; |
| 393 | case ARCH_FRAME: |
| 394 | fprintf_unfiltered (file, "ARCH_FRAME"); |
| 395 | return; |
| 396 | case SENTINEL_FRAME: |
| 397 | fprintf_unfiltered (file, "SENTINEL_FRAME"); |
| 398 | return; |
| 399 | default: |
| 400 | fprintf_unfiltered (file, "<unknown type>"); |
| 401 | return; |
| 402 | }; |
| 403 | } |
| 404 | |
| 405 | static void |
| 406 | fprint_frame (struct ui_file *file, struct frame_info *fi) |
| 407 | { |
| 408 | if (fi == NULL) |
| 409 | { |
| 410 | fprintf_unfiltered (file, "<NULL frame>"); |
| 411 | return; |
| 412 | } |
| 413 | fprintf_unfiltered (file, "{"); |
| 414 | fprintf_unfiltered (file, "level=%d", fi->level); |
| 415 | fprintf_unfiltered (file, ","); |
| 416 | fprintf_unfiltered (file, "type="); |
| 417 | if (fi->unwind != NULL) |
| 418 | fprint_frame_type (file, fi->unwind->type); |
| 419 | else |
| 420 | fprintf_unfiltered (file, "<unknown>"); |
| 421 | fprintf_unfiltered (file, ","); |
| 422 | fprintf_unfiltered (file, "unwind="); |
| 423 | if (fi->unwind != NULL) |
| 424 | gdb_print_host_address (fi->unwind, file); |
| 425 | else |
| 426 | fprintf_unfiltered (file, "<unknown>"); |
| 427 | fprintf_unfiltered (file, ","); |
| 428 | fprintf_unfiltered (file, "pc="); |
| 429 | if (fi->next == NULL || fi->next->prev_pc.status == CC_UNKNOWN) |
| 430 | fprintf_unfiltered (file, "<unknown>"); |
| 431 | else if (fi->next->prev_pc.status == CC_VALUE) |
| 432 | fprintf_unfiltered (file, "%s", |
| 433 | hex_string (fi->next->prev_pc.value)); |
| 434 | else if (fi->next->prev_pc.status == CC_NOT_SAVED) |
| 435 | val_print_not_saved (file); |
| 436 | else if (fi->next->prev_pc.status == CC_UNAVAILABLE) |
| 437 | val_print_unavailable (file); |
| 438 | fprintf_unfiltered (file, ","); |
| 439 | fprintf_unfiltered (file, "id="); |
| 440 | if (fi->this_id.p) |
| 441 | fprint_frame_id (file, fi->this_id.value); |
| 442 | else |
| 443 | fprintf_unfiltered (file, "<unknown>"); |
| 444 | fprintf_unfiltered (file, ","); |
| 445 | fprintf_unfiltered (file, "func="); |
| 446 | if (fi->next != NULL && fi->next->prev_func.p) |
| 447 | fprintf_unfiltered (file, "%s", hex_string (fi->next->prev_func.addr)); |
| 448 | else |
| 449 | fprintf_unfiltered (file, "<unknown>"); |
| 450 | fprintf_unfiltered (file, "}"); |
| 451 | } |
| 452 | |
| 453 | /* Given FRAME, return the enclosing frame as found in real frames read-in from |
| 454 | inferior memory. Skip any previous frames which were made up by GDB. |
| 455 | Return FRAME if FRAME is a non-artificial frame. |
| 456 | Return NULL if FRAME is the start of an artificial-only chain. */ |
| 457 | |
| 458 | static struct frame_info * |
| 459 | skip_artificial_frames (struct frame_info *frame) |
| 460 | { |
| 461 | /* Note we use get_prev_frame_always, and not get_prev_frame. The |
| 462 | latter will truncate the frame chain, leading to this function |
| 463 | unintentionally returning a null_frame_id (e.g., when the user |
| 464 | sets a backtrace limit). |
| 465 | |
| 466 | Note that for record targets we may get a frame chain that consists |
| 467 | of artificial frames only. */ |
| 468 | while (get_frame_type (frame) == INLINE_FRAME |
| 469 | || get_frame_type (frame) == TAILCALL_FRAME) |
| 470 | { |
| 471 | frame = get_prev_frame_always (frame); |
| 472 | if (frame == NULL) |
| 473 | break; |
| 474 | } |
| 475 | |
| 476 | return frame; |
| 477 | } |
| 478 | |
| 479 | struct frame_info * |
| 480 | skip_unwritable_frames (struct frame_info *frame) |
| 481 | { |
| 482 | while (gdbarch_code_of_frame_writable (get_frame_arch (frame), frame) == 0) |
| 483 | { |
| 484 | frame = get_prev_frame (frame); |
| 485 | if (frame == NULL) |
| 486 | break; |
| 487 | } |
| 488 | |
| 489 | return frame; |
| 490 | } |
| 491 | |
| 492 | /* See frame.h. */ |
| 493 | |
| 494 | struct frame_info * |
| 495 | skip_tailcall_frames (struct frame_info *frame) |
| 496 | { |
| 497 | while (get_frame_type (frame) == TAILCALL_FRAME) |
| 498 | { |
| 499 | /* Note that for record targets we may get a frame chain that consists of |
| 500 | tailcall frames only. */ |
| 501 | frame = get_prev_frame (frame); |
| 502 | if (frame == NULL) |
| 503 | break; |
| 504 | } |
| 505 | |
| 506 | return frame; |
| 507 | } |
| 508 | |
| 509 | /* Compute the frame's uniq ID that can be used to, later, re-find the |
| 510 | frame. */ |
| 511 | |
| 512 | static void |
| 513 | compute_frame_id (struct frame_info *fi) |
| 514 | { |
| 515 | gdb_assert (!fi->this_id.p); |
| 516 | |
| 517 | if (frame_debug) |
| 518 | fprintf_unfiltered (gdb_stdlog, "{ compute_frame_id (fi=%d) ", |
| 519 | fi->level); |
| 520 | /* Find the unwinder. */ |
| 521 | if (fi->unwind == NULL) |
| 522 | frame_unwind_find_by_frame (fi, &fi->prologue_cache); |
| 523 | /* Find THIS frame's ID. */ |
| 524 | /* Default to outermost if no ID is found. */ |
| 525 | fi->this_id.value = outer_frame_id; |
| 526 | fi->unwind->this_id (fi, &fi->prologue_cache, &fi->this_id.value); |
| 527 | gdb_assert (frame_id_p (fi->this_id.value)); |
| 528 | fi->this_id.p = 1; |
| 529 | if (frame_debug) |
| 530 | { |
| 531 | fprintf_unfiltered (gdb_stdlog, "-> "); |
| 532 | fprint_frame_id (gdb_stdlog, fi->this_id.value); |
| 533 | fprintf_unfiltered (gdb_stdlog, " }\n"); |
| 534 | } |
| 535 | } |
| 536 | |
| 537 | /* Return a frame uniq ID that can be used to, later, re-find the |
| 538 | frame. */ |
| 539 | |
| 540 | struct frame_id |
| 541 | get_frame_id (struct frame_info *fi) |
| 542 | { |
| 543 | if (fi == NULL) |
| 544 | return null_frame_id; |
| 545 | |
| 546 | if (!fi->this_id.p) |
| 547 | { |
| 548 | int stashed; |
| 549 | |
| 550 | /* If we haven't computed the frame id yet, then it must be that |
| 551 | this is the current frame. Compute it now, and stash the |
| 552 | result. The IDs of other frames are computed as soon as |
| 553 | they're created, in order to detect cycles. See |
| 554 | get_prev_frame_if_no_cycle. */ |
| 555 | gdb_assert (fi->level == 0); |
| 556 | |
| 557 | /* Compute. */ |
| 558 | compute_frame_id (fi); |
| 559 | |
| 560 | /* Since this is the first frame in the chain, this should |
| 561 | always succeed. */ |
| 562 | stashed = frame_stash_add (fi); |
| 563 | gdb_assert (stashed); |
| 564 | } |
| 565 | |
| 566 | return fi->this_id.value; |
| 567 | } |
| 568 | |
| 569 | struct frame_id |
| 570 | get_stack_frame_id (struct frame_info *next_frame) |
| 571 | { |
| 572 | return get_frame_id (skip_artificial_frames (next_frame)); |
| 573 | } |
| 574 | |
| 575 | struct frame_id |
| 576 | frame_unwind_caller_id (struct frame_info *next_frame) |
| 577 | { |
| 578 | struct frame_info *this_frame; |
| 579 | |
| 580 | /* Use get_prev_frame_always, and not get_prev_frame. The latter |
| 581 | will truncate the frame chain, leading to this function |
| 582 | unintentionally returning a null_frame_id (e.g., when a caller |
| 583 | requests the frame ID of "main()"s caller. */ |
| 584 | |
| 585 | next_frame = skip_artificial_frames (next_frame); |
| 586 | if (next_frame == NULL) |
| 587 | return null_frame_id; |
| 588 | |
| 589 | this_frame = get_prev_frame_always (next_frame); |
| 590 | if (this_frame) |
| 591 | return get_frame_id (skip_artificial_frames (this_frame)); |
| 592 | else |
| 593 | return null_frame_id; |
| 594 | } |
| 595 | |
| 596 | const struct frame_id null_frame_id = { 0 }; /* All zeros. */ |
| 597 | const struct frame_id sentinel_frame_id = { 0, 0, 0, FID_STACK_SENTINEL, 0, 1, 0 }; |
| 598 | const struct frame_id outer_frame_id = { 0, 0, 0, FID_STACK_INVALID, 0, 1, 0 }; |
| 599 | |
| 600 | struct frame_id |
| 601 | frame_id_build_special (CORE_ADDR stack_addr, CORE_ADDR code_addr, |
| 602 | CORE_ADDR special_addr) |
| 603 | { |
| 604 | struct frame_id id = null_frame_id; |
| 605 | |
| 606 | id.stack_addr = stack_addr; |
| 607 | id.stack_status = FID_STACK_VALID; |
| 608 | id.code_addr = code_addr; |
| 609 | id.code_addr_p = 1; |
| 610 | id.special_addr = special_addr; |
| 611 | id.special_addr_p = 1; |
| 612 | return id; |
| 613 | } |
| 614 | |
| 615 | /* See frame.h. */ |
| 616 | |
| 617 | struct frame_id |
| 618 | frame_id_build_unavailable_stack (CORE_ADDR code_addr) |
| 619 | { |
| 620 | struct frame_id id = null_frame_id; |
| 621 | |
| 622 | id.stack_status = FID_STACK_UNAVAILABLE; |
| 623 | id.code_addr = code_addr; |
| 624 | id.code_addr_p = 1; |
| 625 | return id; |
| 626 | } |
| 627 | |
| 628 | /* See frame.h. */ |
| 629 | |
| 630 | struct frame_id |
| 631 | frame_id_build_unavailable_stack_special (CORE_ADDR code_addr, |
| 632 | CORE_ADDR special_addr) |
| 633 | { |
| 634 | struct frame_id id = null_frame_id; |
| 635 | |
| 636 | id.stack_status = FID_STACK_UNAVAILABLE; |
| 637 | id.code_addr = code_addr; |
| 638 | id.code_addr_p = 1; |
| 639 | id.special_addr = special_addr; |
| 640 | id.special_addr_p = 1; |
| 641 | return id; |
| 642 | } |
| 643 | |
| 644 | struct frame_id |
| 645 | frame_id_build (CORE_ADDR stack_addr, CORE_ADDR code_addr) |
| 646 | { |
| 647 | struct frame_id id = null_frame_id; |
| 648 | |
| 649 | id.stack_addr = stack_addr; |
| 650 | id.stack_status = FID_STACK_VALID; |
| 651 | id.code_addr = code_addr; |
| 652 | id.code_addr_p = 1; |
| 653 | return id; |
| 654 | } |
| 655 | |
| 656 | struct frame_id |
| 657 | frame_id_build_wild (CORE_ADDR stack_addr) |
| 658 | { |
| 659 | struct frame_id id = null_frame_id; |
| 660 | |
| 661 | id.stack_addr = stack_addr; |
| 662 | id.stack_status = FID_STACK_VALID; |
| 663 | return id; |
| 664 | } |
| 665 | |
| 666 | int |
| 667 | frame_id_p (struct frame_id l) |
| 668 | { |
| 669 | int p; |
| 670 | |
| 671 | /* The frame is valid iff it has a valid stack address. */ |
| 672 | p = l.stack_status != FID_STACK_INVALID; |
| 673 | /* outer_frame_id is also valid. */ |
| 674 | if (!p && memcmp (&l, &outer_frame_id, sizeof (l)) == 0) |
| 675 | p = 1; |
| 676 | if (frame_debug) |
| 677 | { |
| 678 | fprintf_unfiltered (gdb_stdlog, "{ frame_id_p (l="); |
| 679 | fprint_frame_id (gdb_stdlog, l); |
| 680 | fprintf_unfiltered (gdb_stdlog, ") -> %d }\n", p); |
| 681 | } |
| 682 | return p; |
| 683 | } |
| 684 | |
| 685 | int |
| 686 | frame_id_artificial_p (struct frame_id l) |
| 687 | { |
| 688 | if (!frame_id_p (l)) |
| 689 | return 0; |
| 690 | |
| 691 | return (l.artificial_depth != 0); |
| 692 | } |
| 693 | |
| 694 | int |
| 695 | frame_id_eq (struct frame_id l, struct frame_id r) |
| 696 | { |
| 697 | int eq; |
| 698 | |
| 699 | if (l.stack_status == FID_STACK_INVALID && l.special_addr_p |
| 700 | && r.stack_status == FID_STACK_INVALID && r.special_addr_p) |
| 701 | /* The outermost frame marker is equal to itself. This is the |
| 702 | dodgy thing about outer_frame_id, since between execution steps |
| 703 | we might step into another function - from which we can't |
| 704 | unwind either. More thought required to get rid of |
| 705 | outer_frame_id. */ |
| 706 | eq = 1; |
| 707 | else if (l.stack_status == FID_STACK_INVALID |
| 708 | || r.stack_status == FID_STACK_INVALID) |
| 709 | /* Like a NaN, if either ID is invalid, the result is false. |
| 710 | Note that a frame ID is invalid iff it is the null frame ID. */ |
| 711 | eq = 0; |
| 712 | else if (l.stack_status != r.stack_status || l.stack_addr != r.stack_addr) |
| 713 | /* If .stack addresses are different, the frames are different. */ |
| 714 | eq = 0; |
| 715 | else if (l.code_addr_p && r.code_addr_p && l.code_addr != r.code_addr) |
| 716 | /* An invalid code addr is a wild card. If .code addresses are |
| 717 | different, the frames are different. */ |
| 718 | eq = 0; |
| 719 | else if (l.special_addr_p && r.special_addr_p |
| 720 | && l.special_addr != r.special_addr) |
| 721 | /* An invalid special addr is a wild card (or unused). Otherwise |
| 722 | if special addresses are different, the frames are different. */ |
| 723 | eq = 0; |
| 724 | else if (l.artificial_depth != r.artificial_depth) |
| 725 | /* If artifical depths are different, the frames must be different. */ |
| 726 | eq = 0; |
| 727 | else |
| 728 | /* Frames are equal. */ |
| 729 | eq = 1; |
| 730 | |
| 731 | if (frame_debug) |
| 732 | { |
| 733 | fprintf_unfiltered (gdb_stdlog, "{ frame_id_eq (l="); |
| 734 | fprint_frame_id (gdb_stdlog, l); |
| 735 | fprintf_unfiltered (gdb_stdlog, ",r="); |
| 736 | fprint_frame_id (gdb_stdlog, r); |
| 737 | fprintf_unfiltered (gdb_stdlog, ") -> %d }\n", eq); |
| 738 | } |
| 739 | return eq; |
| 740 | } |
| 741 | |
| 742 | /* Safety net to check whether frame ID L should be inner to |
| 743 | frame ID R, according to their stack addresses. |
| 744 | |
| 745 | This method cannot be used to compare arbitrary frames, as the |
| 746 | ranges of valid stack addresses may be discontiguous (e.g. due |
| 747 | to sigaltstack). |
| 748 | |
| 749 | However, it can be used as safety net to discover invalid frame |
| 750 | IDs in certain circumstances. Assuming that NEXT is the immediate |
| 751 | inner frame to THIS and that NEXT and THIS are both NORMAL frames: |
| 752 | |
| 753 | * The stack address of NEXT must be inner-than-or-equal to the stack |
| 754 | address of THIS. |
| 755 | |
| 756 | Therefore, if frame_id_inner (THIS, NEXT) holds, some unwind |
| 757 | error has occurred. |
| 758 | |
| 759 | * If NEXT and THIS have different stack addresses, no other frame |
| 760 | in the frame chain may have a stack address in between. |
| 761 | |
| 762 | Therefore, if frame_id_inner (TEST, THIS) holds, but |
| 763 | frame_id_inner (TEST, NEXT) does not hold, TEST cannot refer |
| 764 | to a valid frame in the frame chain. |
| 765 | |
| 766 | The sanity checks above cannot be performed when a SIGTRAMP frame |
| 767 | is involved, because signal handlers might be executed on a different |
| 768 | stack than the stack used by the routine that caused the signal |
| 769 | to be raised. This can happen for instance when a thread exceeds |
| 770 | its maximum stack size. In this case, certain compilers implement |
| 771 | a stack overflow strategy that cause the handler to be run on a |
| 772 | different stack. */ |
| 773 | |
| 774 | static int |
| 775 | frame_id_inner (struct gdbarch *gdbarch, struct frame_id l, struct frame_id r) |
| 776 | { |
| 777 | int inner; |
| 778 | |
| 779 | if (l.stack_status != FID_STACK_VALID || r.stack_status != FID_STACK_VALID) |
| 780 | /* Like NaN, any operation involving an invalid ID always fails. |
| 781 | Likewise if either ID has an unavailable stack address. */ |
| 782 | inner = 0; |
| 783 | else if (l.artificial_depth > r.artificial_depth |
| 784 | && l.stack_addr == r.stack_addr |
| 785 | && l.code_addr_p == r.code_addr_p |
| 786 | && l.special_addr_p == r.special_addr_p |
| 787 | && l.special_addr == r.special_addr) |
| 788 | { |
| 789 | /* Same function, different inlined functions. */ |
| 790 | const struct block *lb, *rb; |
| 791 | |
| 792 | gdb_assert (l.code_addr_p && r.code_addr_p); |
| 793 | |
| 794 | lb = block_for_pc (l.code_addr); |
| 795 | rb = block_for_pc (r.code_addr); |
| 796 | |
| 797 | if (lb == NULL || rb == NULL) |
| 798 | /* Something's gone wrong. */ |
| 799 | inner = 0; |
| 800 | else |
| 801 | /* This will return true if LB and RB are the same block, or |
| 802 | if the block with the smaller depth lexically encloses the |
| 803 | block with the greater depth. */ |
| 804 | inner = contained_in (lb, rb); |
| 805 | } |
| 806 | else |
| 807 | /* Only return non-zero when strictly inner than. Note that, per |
| 808 | comment in "frame.h", there is some fuzz here. Frameless |
| 809 | functions are not strictly inner than (same .stack but |
| 810 | different .code and/or .special address). */ |
| 811 | inner = gdbarch_inner_than (gdbarch, l.stack_addr, r.stack_addr); |
| 812 | if (frame_debug) |
| 813 | { |
| 814 | fprintf_unfiltered (gdb_stdlog, "{ frame_id_inner (l="); |
| 815 | fprint_frame_id (gdb_stdlog, l); |
| 816 | fprintf_unfiltered (gdb_stdlog, ",r="); |
| 817 | fprint_frame_id (gdb_stdlog, r); |
| 818 | fprintf_unfiltered (gdb_stdlog, ") -> %d }\n", inner); |
| 819 | } |
| 820 | return inner; |
| 821 | } |
| 822 | |
| 823 | struct frame_info * |
| 824 | frame_find_by_id (struct frame_id id) |
| 825 | { |
| 826 | struct frame_info *frame, *prev_frame; |
| 827 | |
| 828 | /* ZERO denotes the null frame, let the caller decide what to do |
| 829 | about it. Should it instead return get_current_frame()? */ |
| 830 | if (!frame_id_p (id)) |
| 831 | return NULL; |
| 832 | |
| 833 | /* Check for the sentinel frame. */ |
| 834 | if (frame_id_eq (id, sentinel_frame_id)) |
| 835 | return sentinel_frame; |
| 836 | |
| 837 | /* Try using the frame stash first. Finding it there removes the need |
| 838 | to perform the search by looping over all frames, which can be very |
| 839 | CPU-intensive if the number of frames is very high (the loop is O(n) |
| 840 | and get_prev_frame performs a series of checks that are relatively |
| 841 | expensive). This optimization is particularly useful when this function |
| 842 | is called from another function (such as value_fetch_lazy, case |
| 843 | VALUE_LVAL (val) == lval_register) which already loops over all frames, |
| 844 | making the overall behavior O(n^2). */ |
| 845 | frame = frame_stash_find (id); |
| 846 | if (frame) |
| 847 | return frame; |
| 848 | |
| 849 | for (frame = get_current_frame (); ; frame = prev_frame) |
| 850 | { |
| 851 | struct frame_id self = get_frame_id (frame); |
| 852 | |
| 853 | if (frame_id_eq (id, self)) |
| 854 | /* An exact match. */ |
| 855 | return frame; |
| 856 | |
| 857 | prev_frame = get_prev_frame (frame); |
| 858 | if (!prev_frame) |
| 859 | return NULL; |
| 860 | |
| 861 | /* As a safety net to avoid unnecessary backtracing while trying |
| 862 | to find an invalid ID, we check for a common situation where |
| 863 | we can detect from comparing stack addresses that no other |
| 864 | frame in the current frame chain can have this ID. See the |
| 865 | comment at frame_id_inner for details. */ |
| 866 | if (get_frame_type (frame) == NORMAL_FRAME |
| 867 | && !frame_id_inner (get_frame_arch (frame), id, self) |
| 868 | && frame_id_inner (get_frame_arch (prev_frame), id, |
| 869 | get_frame_id (prev_frame))) |
| 870 | return NULL; |
| 871 | } |
| 872 | return NULL; |
| 873 | } |
| 874 | |
| 875 | static CORE_ADDR |
| 876 | frame_unwind_pc (struct frame_info *this_frame) |
| 877 | { |
| 878 | if (this_frame->prev_pc.status == CC_UNKNOWN) |
| 879 | { |
| 880 | struct gdbarch *prev_gdbarch; |
| 881 | CORE_ADDR pc = 0; |
| 882 | int pc_p = 0; |
| 883 | |
| 884 | /* The right way. The `pure' way. The one true way. This |
| 885 | method depends solely on the register-unwind code to |
| 886 | determine the value of registers in THIS frame, and hence |
| 887 | the value of this frame's PC (resume address). A typical |
| 888 | implementation is no more than: |
| 889 | |
| 890 | frame_unwind_register (this_frame, ISA_PC_REGNUM, buf); |
| 891 | return extract_unsigned_integer (buf, size of ISA_PC_REGNUM); |
| 892 | |
| 893 | Note: this method is very heavily dependent on a correct |
| 894 | register-unwind implementation, it pays to fix that |
| 895 | method first; this method is frame type agnostic, since |
| 896 | it only deals with register values, it works with any |
| 897 | frame. This is all in stark contrast to the old |
| 898 | FRAME_SAVED_PC which would try to directly handle all the |
| 899 | different ways that a PC could be unwound. */ |
| 900 | prev_gdbarch = frame_unwind_arch (this_frame); |
| 901 | |
| 902 | try |
| 903 | { |
| 904 | pc = gdbarch_unwind_pc (prev_gdbarch, this_frame); |
| 905 | pc_p = 1; |
| 906 | } |
| 907 | catch (const gdb_exception_error &ex) |
| 908 | { |
| 909 | if (ex.error == NOT_AVAILABLE_ERROR) |
| 910 | { |
| 911 | this_frame->prev_pc.status = CC_UNAVAILABLE; |
| 912 | |
| 913 | if (frame_debug) |
| 914 | fprintf_unfiltered (gdb_stdlog, |
| 915 | "{ frame_unwind_pc (this_frame=%d)" |
| 916 | " -> <unavailable> }\n", |
| 917 | this_frame->level); |
| 918 | } |
| 919 | else if (ex.error == OPTIMIZED_OUT_ERROR) |
| 920 | { |
| 921 | this_frame->prev_pc.status = CC_NOT_SAVED; |
| 922 | |
| 923 | if (frame_debug) |
| 924 | fprintf_unfiltered (gdb_stdlog, |
| 925 | "{ frame_unwind_pc (this_frame=%d)" |
| 926 | " -> <not saved> }\n", |
| 927 | this_frame->level); |
| 928 | } |
| 929 | else |
| 930 | throw; |
| 931 | } |
| 932 | |
| 933 | if (pc_p) |
| 934 | { |
| 935 | this_frame->prev_pc.value = pc; |
| 936 | this_frame->prev_pc.status = CC_VALUE; |
| 937 | if (frame_debug) |
| 938 | fprintf_unfiltered (gdb_stdlog, |
| 939 | "{ frame_unwind_pc (this_frame=%d) " |
| 940 | "-> %s }\n", |
| 941 | this_frame->level, |
| 942 | hex_string (this_frame->prev_pc.value)); |
| 943 | } |
| 944 | } |
| 945 | |
| 946 | if (this_frame->prev_pc.status == CC_VALUE) |
| 947 | return this_frame->prev_pc.value; |
| 948 | else if (this_frame->prev_pc.status == CC_UNAVAILABLE) |
| 949 | throw_error (NOT_AVAILABLE_ERROR, _("PC not available")); |
| 950 | else if (this_frame->prev_pc.status == CC_NOT_SAVED) |
| 951 | throw_error (OPTIMIZED_OUT_ERROR, _("PC not saved")); |
| 952 | else |
| 953 | internal_error (__FILE__, __LINE__, |
| 954 | "unexpected prev_pc status: %d", |
| 955 | (int) this_frame->prev_pc.status); |
| 956 | } |
| 957 | |
| 958 | CORE_ADDR |
| 959 | frame_unwind_caller_pc (struct frame_info *this_frame) |
| 960 | { |
| 961 | this_frame = skip_artificial_frames (this_frame); |
| 962 | |
| 963 | /* We must have a non-artificial frame. The caller is supposed to check |
| 964 | the result of frame_unwind_caller_id (), which returns NULL_FRAME_ID |
| 965 | in this case. */ |
| 966 | gdb_assert (this_frame != NULL); |
| 967 | |
| 968 | return frame_unwind_pc (this_frame); |
| 969 | } |
| 970 | |
| 971 | int |
| 972 | get_frame_func_if_available (struct frame_info *this_frame, CORE_ADDR *pc) |
| 973 | { |
| 974 | struct frame_info *next_frame = this_frame->next; |
| 975 | |
| 976 | if (!next_frame->prev_func.p) |
| 977 | { |
| 978 | CORE_ADDR addr_in_block; |
| 979 | |
| 980 | /* Make certain that this, and not the adjacent, function is |
| 981 | found. */ |
| 982 | if (!get_frame_address_in_block_if_available (this_frame, &addr_in_block)) |
| 983 | { |
| 984 | next_frame->prev_func.p = -1; |
| 985 | if (frame_debug) |
| 986 | fprintf_unfiltered (gdb_stdlog, |
| 987 | "{ get_frame_func (this_frame=%d)" |
| 988 | " -> unavailable }\n", |
| 989 | this_frame->level); |
| 990 | } |
| 991 | else |
| 992 | { |
| 993 | next_frame->prev_func.p = 1; |
| 994 | next_frame->prev_func.addr = get_pc_function_start (addr_in_block); |
| 995 | if (frame_debug) |
| 996 | fprintf_unfiltered (gdb_stdlog, |
| 997 | "{ get_frame_func (this_frame=%d) -> %s }\n", |
| 998 | this_frame->level, |
| 999 | hex_string (next_frame->prev_func.addr)); |
| 1000 | } |
| 1001 | } |
| 1002 | |
| 1003 | if (next_frame->prev_func.p < 0) |
| 1004 | { |
| 1005 | *pc = -1; |
| 1006 | return 0; |
| 1007 | } |
| 1008 | else |
| 1009 | { |
| 1010 | *pc = next_frame->prev_func.addr; |
| 1011 | return 1; |
| 1012 | } |
| 1013 | } |
| 1014 | |
| 1015 | CORE_ADDR |
| 1016 | get_frame_func (struct frame_info *this_frame) |
| 1017 | { |
| 1018 | CORE_ADDR pc; |
| 1019 | |
| 1020 | if (!get_frame_func_if_available (this_frame, &pc)) |
| 1021 | throw_error (NOT_AVAILABLE_ERROR, _("PC not available")); |
| 1022 | |
| 1023 | return pc; |
| 1024 | } |
| 1025 | |
| 1026 | std::unique_ptr<readonly_detached_regcache> |
| 1027 | frame_save_as_regcache (struct frame_info *this_frame) |
| 1028 | { |
| 1029 | auto cooked_read = [this_frame] (int regnum, gdb_byte *buf) |
| 1030 | { |
| 1031 | if (!deprecated_frame_register_read (this_frame, regnum, buf)) |
| 1032 | return REG_UNAVAILABLE; |
| 1033 | else |
| 1034 | return REG_VALID; |
| 1035 | }; |
| 1036 | |
| 1037 | std::unique_ptr<readonly_detached_regcache> regcache |
| 1038 | (new readonly_detached_regcache (get_frame_arch (this_frame), cooked_read)); |
| 1039 | |
| 1040 | return regcache; |
| 1041 | } |
| 1042 | |
| 1043 | void |
| 1044 | frame_pop (struct frame_info *this_frame) |
| 1045 | { |
| 1046 | struct frame_info *prev_frame; |
| 1047 | |
| 1048 | if (get_frame_type (this_frame) == DUMMY_FRAME) |
| 1049 | { |
| 1050 | /* Popping a dummy frame involves restoring more than just registers. |
| 1051 | dummy_frame_pop does all the work. */ |
| 1052 | dummy_frame_pop (get_frame_id (this_frame), inferior_thread ()); |
| 1053 | return; |
| 1054 | } |
| 1055 | |
| 1056 | /* Ensure that we have a frame to pop to. */ |
| 1057 | prev_frame = get_prev_frame_always (this_frame); |
| 1058 | |
| 1059 | if (!prev_frame) |
| 1060 | error (_("Cannot pop the initial frame.")); |
| 1061 | |
| 1062 | /* Ignore TAILCALL_FRAME type frames, they were executed already before |
| 1063 | entering THISFRAME. */ |
| 1064 | prev_frame = skip_tailcall_frames (prev_frame); |
| 1065 | |
| 1066 | if (prev_frame == NULL) |
| 1067 | error (_("Cannot find the caller frame.")); |
| 1068 | |
| 1069 | /* Make a copy of all the register values unwound from this frame. |
| 1070 | Save them in a scratch buffer so that there isn't a race between |
| 1071 | trying to extract the old values from the current regcache while |
| 1072 | at the same time writing new values into that same cache. */ |
| 1073 | std::unique_ptr<readonly_detached_regcache> scratch |
| 1074 | = frame_save_as_regcache (prev_frame); |
| 1075 | |
| 1076 | /* FIXME: cagney/2003-03-16: It should be possible to tell the |
| 1077 | target's register cache that it is about to be hit with a burst |
| 1078 | register transfer and that the sequence of register writes should |
| 1079 | be batched. The pair target_prepare_to_store() and |
| 1080 | target_store_registers() kind of suggest this functionality. |
| 1081 | Unfortunately, they don't implement it. Their lack of a formal |
| 1082 | definition can lead to targets writing back bogus values |
| 1083 | (arguably a bug in the target code mind). */ |
| 1084 | /* Now copy those saved registers into the current regcache. */ |
| 1085 | get_current_regcache ()->restore (scratch.get ()); |
| 1086 | |
| 1087 | /* We've made right mess of GDB's local state, just discard |
| 1088 | everything. */ |
| 1089 | reinit_frame_cache (); |
| 1090 | } |
| 1091 | |
| 1092 | void |
| 1093 | frame_register_unwind (frame_info *next_frame, int regnum, |
| 1094 | int *optimizedp, int *unavailablep, |
| 1095 | enum lval_type *lvalp, CORE_ADDR *addrp, |
| 1096 | int *realnump, gdb_byte *bufferp) |
| 1097 | { |
| 1098 | struct value *value; |
| 1099 | |
| 1100 | /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates |
| 1101 | that the value proper does not need to be fetched. */ |
| 1102 | gdb_assert (optimizedp != NULL); |
| 1103 | gdb_assert (lvalp != NULL); |
| 1104 | gdb_assert (addrp != NULL); |
| 1105 | gdb_assert (realnump != NULL); |
| 1106 | /* gdb_assert (bufferp != NULL); */ |
| 1107 | |
| 1108 | value = frame_unwind_register_value (next_frame, regnum); |
| 1109 | |
| 1110 | gdb_assert (value != NULL); |
| 1111 | |
| 1112 | *optimizedp = value_optimized_out (value); |
| 1113 | *unavailablep = !value_entirely_available (value); |
| 1114 | *lvalp = VALUE_LVAL (value); |
| 1115 | *addrp = value_address (value); |
| 1116 | if (*lvalp == lval_register) |
| 1117 | *realnump = VALUE_REGNUM (value); |
| 1118 | else |
| 1119 | *realnump = -1; |
| 1120 | |
| 1121 | if (bufferp) |
| 1122 | { |
| 1123 | if (!*optimizedp && !*unavailablep) |
| 1124 | memcpy (bufferp, value_contents_all (value), |
| 1125 | TYPE_LENGTH (value_type (value))); |
| 1126 | else |
| 1127 | memset (bufferp, 0, TYPE_LENGTH (value_type (value))); |
| 1128 | } |
| 1129 | |
| 1130 | /* Dispose of the new value. This prevents watchpoints from |
| 1131 | trying to watch the saved frame pointer. */ |
| 1132 | release_value (value); |
| 1133 | } |
| 1134 | |
| 1135 | void |
| 1136 | frame_register (struct frame_info *frame, int regnum, |
| 1137 | int *optimizedp, int *unavailablep, enum lval_type *lvalp, |
| 1138 | CORE_ADDR *addrp, int *realnump, gdb_byte *bufferp) |
| 1139 | { |
| 1140 | /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates |
| 1141 | that the value proper does not need to be fetched. */ |
| 1142 | gdb_assert (optimizedp != NULL); |
| 1143 | gdb_assert (lvalp != NULL); |
| 1144 | gdb_assert (addrp != NULL); |
| 1145 | gdb_assert (realnump != NULL); |
| 1146 | /* gdb_assert (bufferp != NULL); */ |
| 1147 | |
| 1148 | /* Obtain the register value by unwinding the register from the next |
| 1149 | (more inner frame). */ |
| 1150 | gdb_assert (frame != NULL && frame->next != NULL); |
| 1151 | frame_register_unwind (frame->next, regnum, optimizedp, unavailablep, |
| 1152 | lvalp, addrp, realnump, bufferp); |
| 1153 | } |
| 1154 | |
| 1155 | void |
| 1156 | frame_unwind_register (frame_info *next_frame, int regnum, gdb_byte *buf) |
| 1157 | { |
| 1158 | int optimized; |
| 1159 | int unavailable; |
| 1160 | CORE_ADDR addr; |
| 1161 | int realnum; |
| 1162 | enum lval_type lval; |
| 1163 | |
| 1164 | frame_register_unwind (next_frame, regnum, &optimized, &unavailable, |
| 1165 | &lval, &addr, &realnum, buf); |
| 1166 | |
| 1167 | if (optimized) |
| 1168 | throw_error (OPTIMIZED_OUT_ERROR, |
| 1169 | _("Register %d was not saved"), regnum); |
| 1170 | if (unavailable) |
| 1171 | throw_error (NOT_AVAILABLE_ERROR, |
| 1172 | _("Register %d is not available"), regnum); |
| 1173 | } |
| 1174 | |
| 1175 | void |
| 1176 | get_frame_register (struct frame_info *frame, |
| 1177 | int regnum, gdb_byte *buf) |
| 1178 | { |
| 1179 | frame_unwind_register (frame->next, regnum, buf); |
| 1180 | } |
| 1181 | |
| 1182 | struct value * |
| 1183 | frame_unwind_register_value (frame_info *next_frame, int regnum) |
| 1184 | { |
| 1185 | struct gdbarch *gdbarch; |
| 1186 | struct value *value; |
| 1187 | |
| 1188 | gdb_assert (next_frame != NULL); |
| 1189 | gdbarch = frame_unwind_arch (next_frame); |
| 1190 | |
| 1191 | if (frame_debug) |
| 1192 | { |
| 1193 | fprintf_unfiltered (gdb_stdlog, |
| 1194 | "{ frame_unwind_register_value " |
| 1195 | "(frame=%d,regnum=%d(%s),...) ", |
| 1196 | next_frame->level, regnum, |
| 1197 | user_reg_map_regnum_to_name (gdbarch, regnum)); |
| 1198 | } |
| 1199 | |
| 1200 | /* Find the unwinder. */ |
| 1201 | if (next_frame->unwind == NULL) |
| 1202 | frame_unwind_find_by_frame (next_frame, &next_frame->prologue_cache); |
| 1203 | |
| 1204 | /* Ask this frame to unwind its register. */ |
| 1205 | value = next_frame->unwind->prev_register (next_frame, |
| 1206 | &next_frame->prologue_cache, |
| 1207 | regnum); |
| 1208 | |
| 1209 | if (frame_debug) |
| 1210 | { |
| 1211 | fprintf_unfiltered (gdb_stdlog, "->"); |
| 1212 | if (value_optimized_out (value)) |
| 1213 | { |
| 1214 | fprintf_unfiltered (gdb_stdlog, " "); |
| 1215 | val_print_optimized_out (value, gdb_stdlog); |
| 1216 | } |
| 1217 | else |
| 1218 | { |
| 1219 | if (VALUE_LVAL (value) == lval_register) |
| 1220 | fprintf_unfiltered (gdb_stdlog, " register=%d", |
| 1221 | VALUE_REGNUM (value)); |
| 1222 | else if (VALUE_LVAL (value) == lval_memory) |
| 1223 | fprintf_unfiltered (gdb_stdlog, " address=%s", |
| 1224 | paddress (gdbarch, |
| 1225 | value_address (value))); |
| 1226 | else |
| 1227 | fprintf_unfiltered (gdb_stdlog, " computed"); |
| 1228 | |
| 1229 | if (value_lazy (value)) |
| 1230 | fprintf_unfiltered (gdb_stdlog, " lazy"); |
| 1231 | else |
| 1232 | { |
| 1233 | int i; |
| 1234 | const gdb_byte *buf = value_contents (value); |
| 1235 | |
| 1236 | fprintf_unfiltered (gdb_stdlog, " bytes="); |
| 1237 | fprintf_unfiltered (gdb_stdlog, "["); |
| 1238 | for (i = 0; i < register_size (gdbarch, regnum); i++) |
| 1239 | fprintf_unfiltered (gdb_stdlog, "%02x", buf[i]); |
| 1240 | fprintf_unfiltered (gdb_stdlog, "]"); |
| 1241 | } |
| 1242 | } |
| 1243 | |
| 1244 | fprintf_unfiltered (gdb_stdlog, " }\n"); |
| 1245 | } |
| 1246 | |
| 1247 | return value; |
| 1248 | } |
| 1249 | |
| 1250 | struct value * |
| 1251 | get_frame_register_value (struct frame_info *frame, int regnum) |
| 1252 | { |
| 1253 | return frame_unwind_register_value (frame->next, regnum); |
| 1254 | } |
| 1255 | |
| 1256 | LONGEST |
| 1257 | frame_unwind_register_signed (frame_info *next_frame, int regnum) |
| 1258 | { |
| 1259 | struct gdbarch *gdbarch = frame_unwind_arch (next_frame); |
| 1260 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 1261 | int size = register_size (gdbarch, regnum); |
| 1262 | struct value *value = frame_unwind_register_value (next_frame, regnum); |
| 1263 | |
| 1264 | gdb_assert (value != NULL); |
| 1265 | |
| 1266 | if (value_optimized_out (value)) |
| 1267 | { |
| 1268 | throw_error (OPTIMIZED_OUT_ERROR, |
| 1269 | _("Register %d was not saved"), regnum); |
| 1270 | } |
| 1271 | if (!value_entirely_available (value)) |
| 1272 | { |
| 1273 | throw_error (NOT_AVAILABLE_ERROR, |
| 1274 | _("Register %d is not available"), regnum); |
| 1275 | } |
| 1276 | |
| 1277 | LONGEST r = extract_signed_integer (value_contents_all (value), size, |
| 1278 | byte_order); |
| 1279 | |
| 1280 | release_value (value); |
| 1281 | return r; |
| 1282 | } |
| 1283 | |
| 1284 | LONGEST |
| 1285 | get_frame_register_signed (struct frame_info *frame, int regnum) |
| 1286 | { |
| 1287 | return frame_unwind_register_signed (frame->next, regnum); |
| 1288 | } |
| 1289 | |
| 1290 | ULONGEST |
| 1291 | frame_unwind_register_unsigned (frame_info *next_frame, int regnum) |
| 1292 | { |
| 1293 | struct gdbarch *gdbarch = frame_unwind_arch (next_frame); |
| 1294 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 1295 | int size = register_size (gdbarch, regnum); |
| 1296 | struct value *value = frame_unwind_register_value (next_frame, regnum); |
| 1297 | |
| 1298 | gdb_assert (value != NULL); |
| 1299 | |
| 1300 | if (value_optimized_out (value)) |
| 1301 | { |
| 1302 | throw_error (OPTIMIZED_OUT_ERROR, |
| 1303 | _("Register %d was not saved"), regnum); |
| 1304 | } |
| 1305 | if (!value_entirely_available (value)) |
| 1306 | { |
| 1307 | throw_error (NOT_AVAILABLE_ERROR, |
| 1308 | _("Register %d is not available"), regnum); |
| 1309 | } |
| 1310 | |
| 1311 | ULONGEST r = extract_unsigned_integer (value_contents_all (value), size, |
| 1312 | byte_order); |
| 1313 | |
| 1314 | release_value (value); |
| 1315 | return r; |
| 1316 | } |
| 1317 | |
| 1318 | ULONGEST |
| 1319 | get_frame_register_unsigned (struct frame_info *frame, int regnum) |
| 1320 | { |
| 1321 | return frame_unwind_register_unsigned (frame->next, regnum); |
| 1322 | } |
| 1323 | |
| 1324 | int |
| 1325 | read_frame_register_unsigned (struct frame_info *frame, int regnum, |
| 1326 | ULONGEST *val) |
| 1327 | { |
| 1328 | struct value *regval = get_frame_register_value (frame, regnum); |
| 1329 | |
| 1330 | if (!value_optimized_out (regval) |
| 1331 | && value_entirely_available (regval)) |
| 1332 | { |
| 1333 | struct gdbarch *gdbarch = get_frame_arch (frame); |
| 1334 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 1335 | int size = register_size (gdbarch, VALUE_REGNUM (regval)); |
| 1336 | |
| 1337 | *val = extract_unsigned_integer (value_contents (regval), size, byte_order); |
| 1338 | return 1; |
| 1339 | } |
| 1340 | |
| 1341 | return 0; |
| 1342 | } |
| 1343 | |
| 1344 | void |
| 1345 | put_frame_register (struct frame_info *frame, int regnum, |
| 1346 | const gdb_byte *buf) |
| 1347 | { |
| 1348 | struct gdbarch *gdbarch = get_frame_arch (frame); |
| 1349 | int realnum; |
| 1350 | int optim; |
| 1351 | int unavail; |
| 1352 | enum lval_type lval; |
| 1353 | CORE_ADDR addr; |
| 1354 | |
| 1355 | frame_register (frame, regnum, &optim, &unavail, |
| 1356 | &lval, &addr, &realnum, NULL); |
| 1357 | if (optim) |
| 1358 | error (_("Attempt to assign to a register that was not saved.")); |
| 1359 | switch (lval) |
| 1360 | { |
| 1361 | case lval_memory: |
| 1362 | { |
| 1363 | write_memory (addr, buf, register_size (gdbarch, regnum)); |
| 1364 | break; |
| 1365 | } |
| 1366 | case lval_register: |
| 1367 | get_current_regcache ()->cooked_write (realnum, buf); |
| 1368 | break; |
| 1369 | default: |
| 1370 | error (_("Attempt to assign to an unmodifiable value.")); |
| 1371 | } |
| 1372 | } |
| 1373 | |
| 1374 | /* This function is deprecated. Use get_frame_register_value instead, |
| 1375 | which provides more accurate information. |
| 1376 | |
| 1377 | Find and return the value of REGNUM for the specified stack frame. |
| 1378 | The number of bytes copied is REGISTER_SIZE (REGNUM). |
| 1379 | |
| 1380 | Returns 0 if the register value could not be found. */ |
| 1381 | |
| 1382 | int |
| 1383 | deprecated_frame_register_read (struct frame_info *frame, int regnum, |
| 1384 | gdb_byte *myaddr) |
| 1385 | { |
| 1386 | int optimized; |
| 1387 | int unavailable; |
| 1388 | enum lval_type lval; |
| 1389 | CORE_ADDR addr; |
| 1390 | int realnum; |
| 1391 | |
| 1392 | frame_register (frame, regnum, &optimized, &unavailable, |
| 1393 | &lval, &addr, &realnum, myaddr); |
| 1394 | |
| 1395 | return !optimized && !unavailable; |
| 1396 | } |
| 1397 | |
| 1398 | int |
| 1399 | get_frame_register_bytes (struct frame_info *frame, int regnum, |
| 1400 | CORE_ADDR offset, int len, gdb_byte *myaddr, |
| 1401 | int *optimizedp, int *unavailablep) |
| 1402 | { |
| 1403 | struct gdbarch *gdbarch = get_frame_arch (frame); |
| 1404 | int i; |
| 1405 | int maxsize; |
| 1406 | int numregs; |
| 1407 | |
| 1408 | /* Skip registers wholly inside of OFFSET. */ |
| 1409 | while (offset >= register_size (gdbarch, regnum)) |
| 1410 | { |
| 1411 | offset -= register_size (gdbarch, regnum); |
| 1412 | regnum++; |
| 1413 | } |
| 1414 | |
| 1415 | /* Ensure that we will not read beyond the end of the register file. |
| 1416 | This can only ever happen if the debug information is bad. */ |
| 1417 | maxsize = -offset; |
| 1418 | numregs = gdbarch_num_cooked_regs (gdbarch); |
| 1419 | for (i = regnum; i < numregs; i++) |
| 1420 | { |
| 1421 | int thissize = register_size (gdbarch, i); |
| 1422 | |
| 1423 | if (thissize == 0) |
| 1424 | break; /* This register is not available on this architecture. */ |
| 1425 | maxsize += thissize; |
| 1426 | } |
| 1427 | if (len > maxsize) |
| 1428 | error (_("Bad debug information detected: " |
| 1429 | "Attempt to read %d bytes from registers."), len); |
| 1430 | |
| 1431 | /* Copy the data. */ |
| 1432 | while (len > 0) |
| 1433 | { |
| 1434 | int curr_len = register_size (gdbarch, regnum) - offset; |
| 1435 | |
| 1436 | if (curr_len > len) |
| 1437 | curr_len = len; |
| 1438 | |
| 1439 | if (curr_len == register_size (gdbarch, regnum)) |
| 1440 | { |
| 1441 | enum lval_type lval; |
| 1442 | CORE_ADDR addr; |
| 1443 | int realnum; |
| 1444 | |
| 1445 | frame_register (frame, regnum, optimizedp, unavailablep, |
| 1446 | &lval, &addr, &realnum, myaddr); |
| 1447 | if (*optimizedp || *unavailablep) |
| 1448 | return 0; |
| 1449 | } |
| 1450 | else |
| 1451 | { |
| 1452 | struct value *value = frame_unwind_register_value (frame->next, |
| 1453 | regnum); |
| 1454 | gdb_assert (value != NULL); |
| 1455 | *optimizedp = value_optimized_out (value); |
| 1456 | *unavailablep = !value_entirely_available (value); |
| 1457 | |
| 1458 | if (*optimizedp || *unavailablep) |
| 1459 | { |
| 1460 | release_value (value); |
| 1461 | return 0; |
| 1462 | } |
| 1463 | memcpy (myaddr, value_contents_all (value) + offset, curr_len); |
| 1464 | release_value (value); |
| 1465 | } |
| 1466 | |
| 1467 | myaddr += curr_len; |
| 1468 | len -= curr_len; |
| 1469 | offset = 0; |
| 1470 | regnum++; |
| 1471 | } |
| 1472 | |
| 1473 | *optimizedp = 0; |
| 1474 | *unavailablep = 0; |
| 1475 | return 1; |
| 1476 | } |
| 1477 | |
| 1478 | void |
| 1479 | put_frame_register_bytes (struct frame_info *frame, int regnum, |
| 1480 | CORE_ADDR offset, int len, const gdb_byte *myaddr) |
| 1481 | { |
| 1482 | struct gdbarch *gdbarch = get_frame_arch (frame); |
| 1483 | |
| 1484 | /* Skip registers wholly inside of OFFSET. */ |
| 1485 | while (offset >= register_size (gdbarch, regnum)) |
| 1486 | { |
| 1487 | offset -= register_size (gdbarch, regnum); |
| 1488 | regnum++; |
| 1489 | } |
| 1490 | |
| 1491 | /* Copy the data. */ |
| 1492 | while (len > 0) |
| 1493 | { |
| 1494 | int curr_len = register_size (gdbarch, regnum) - offset; |
| 1495 | |
| 1496 | if (curr_len > len) |
| 1497 | curr_len = len; |
| 1498 | |
| 1499 | if (curr_len == register_size (gdbarch, regnum)) |
| 1500 | { |
| 1501 | put_frame_register (frame, regnum, myaddr); |
| 1502 | } |
| 1503 | else |
| 1504 | { |
| 1505 | struct value *value = frame_unwind_register_value (frame->next, |
| 1506 | regnum); |
| 1507 | gdb_assert (value != NULL); |
| 1508 | |
| 1509 | memcpy ((char *) value_contents_writeable (value) + offset, myaddr, |
| 1510 | curr_len); |
| 1511 | put_frame_register (frame, regnum, value_contents_raw (value)); |
| 1512 | release_value (value); |
| 1513 | } |
| 1514 | |
| 1515 | myaddr += curr_len; |
| 1516 | len -= curr_len; |
| 1517 | offset = 0; |
| 1518 | regnum++; |
| 1519 | } |
| 1520 | } |
| 1521 | |
| 1522 | /* Create a sentinel frame. */ |
| 1523 | |
| 1524 | static struct frame_info * |
| 1525 | create_sentinel_frame (struct program_space *pspace, struct regcache *regcache) |
| 1526 | { |
| 1527 | struct frame_info *frame = FRAME_OBSTACK_ZALLOC (struct frame_info); |
| 1528 | |
| 1529 | frame->level = -1; |
| 1530 | frame->pspace = pspace; |
| 1531 | frame->aspace = regcache->aspace (); |
| 1532 | /* Explicitly initialize the sentinel frame's cache. Provide it |
| 1533 | with the underlying regcache. In the future additional |
| 1534 | information, such as the frame's thread will be added. */ |
| 1535 | frame->prologue_cache = sentinel_frame_cache (regcache); |
| 1536 | /* For the moment there is only one sentinel frame implementation. */ |
| 1537 | frame->unwind = &sentinel_frame_unwind; |
| 1538 | /* Link this frame back to itself. The frame is self referential |
| 1539 | (the unwound PC is the same as the pc), so make it so. */ |
| 1540 | frame->next = frame; |
| 1541 | /* The sentinel frame has a special ID. */ |
| 1542 | frame->this_id.p = 1; |
| 1543 | frame->this_id.value = sentinel_frame_id; |
| 1544 | if (frame_debug) |
| 1545 | { |
| 1546 | fprintf_unfiltered (gdb_stdlog, "{ create_sentinel_frame (...) -> "); |
| 1547 | fprint_frame (gdb_stdlog, frame); |
| 1548 | fprintf_unfiltered (gdb_stdlog, " }\n"); |
| 1549 | } |
| 1550 | return frame; |
| 1551 | } |
| 1552 | |
| 1553 | /* Cache for frame addresses already read by gdb. Valid only while |
| 1554 | inferior is stopped. Control variables for the frame cache should |
| 1555 | be local to this module. */ |
| 1556 | |
| 1557 | static struct obstack frame_cache_obstack; |
| 1558 | |
| 1559 | void * |
| 1560 | frame_obstack_zalloc (unsigned long size) |
| 1561 | { |
| 1562 | void *data = obstack_alloc (&frame_cache_obstack, size); |
| 1563 | |
| 1564 | memset (data, 0, size); |
| 1565 | return data; |
| 1566 | } |
| 1567 | |
| 1568 | static struct frame_info *get_prev_frame_always_1 (struct frame_info *this_frame); |
| 1569 | |
| 1570 | struct frame_info * |
| 1571 | get_current_frame (void) |
| 1572 | { |
| 1573 | struct frame_info *current_frame; |
| 1574 | |
| 1575 | /* First check, and report, the lack of registers. Having GDB |
| 1576 | report "No stack!" or "No memory" when the target doesn't even |
| 1577 | have registers is very confusing. Besides, "printcmd.exp" |
| 1578 | explicitly checks that ``print $pc'' with no registers prints "No |
| 1579 | registers". */ |
| 1580 | if (!target_has_registers) |
| 1581 | error (_("No registers.")); |
| 1582 | if (!target_has_stack) |
| 1583 | error (_("No stack.")); |
| 1584 | if (!target_has_memory) |
| 1585 | error (_("No memory.")); |
| 1586 | /* Traceframes are effectively a substitute for the live inferior. */ |
| 1587 | if (get_traceframe_number () < 0) |
| 1588 | validate_registers_access (); |
| 1589 | |
| 1590 | if (sentinel_frame == NULL) |
| 1591 | sentinel_frame = |
| 1592 | create_sentinel_frame (current_program_space, get_current_regcache ()); |
| 1593 | |
| 1594 | /* Set the current frame before computing the frame id, to avoid |
| 1595 | recursion inside compute_frame_id, in case the frame's |
| 1596 | unwinder decides to do a symbol lookup (which depends on the |
| 1597 | selected frame's block). |
| 1598 | |
| 1599 | This call must always succeed. In particular, nothing inside |
| 1600 | get_prev_frame_always_1 should try to unwind from the |
| 1601 | sentinel frame, because that could fail/throw, and we always |
| 1602 | want to leave with the current frame created and linked in -- |
| 1603 | we should never end up with the sentinel frame as outermost |
| 1604 | frame. */ |
| 1605 | current_frame = get_prev_frame_always_1 (sentinel_frame); |
| 1606 | gdb_assert (current_frame != NULL); |
| 1607 | |
| 1608 | return current_frame; |
| 1609 | } |
| 1610 | |
| 1611 | /* The "selected" stack frame is used by default for local and arg |
| 1612 | access. May be zero, for no selected frame. */ |
| 1613 | |
| 1614 | static struct frame_info *selected_frame; |
| 1615 | |
| 1616 | int |
| 1617 | has_stack_frames (void) |
| 1618 | { |
| 1619 | if (!target_has_registers || !target_has_stack || !target_has_memory) |
| 1620 | return 0; |
| 1621 | |
| 1622 | /* Traceframes are effectively a substitute for the live inferior. */ |
| 1623 | if (get_traceframe_number () < 0) |
| 1624 | { |
| 1625 | /* No current inferior, no frame. */ |
| 1626 | if (inferior_ptid == null_ptid) |
| 1627 | return 0; |
| 1628 | |
| 1629 | thread_info *tp = inferior_thread (); |
| 1630 | /* Don't try to read from a dead thread. */ |
| 1631 | if (tp->state == THREAD_EXITED) |
| 1632 | return 0; |
| 1633 | |
| 1634 | /* ... or from a spinning thread. */ |
| 1635 | if (tp->executing) |
| 1636 | return 0; |
| 1637 | } |
| 1638 | |
| 1639 | return 1; |
| 1640 | } |
| 1641 | |
| 1642 | /* Return the selected frame. Always non-NULL (unless there isn't an |
| 1643 | inferior sufficient for creating a frame) in which case an error is |
| 1644 | thrown. */ |
| 1645 | |
| 1646 | struct frame_info * |
| 1647 | get_selected_frame (const char *message) |
| 1648 | { |
| 1649 | if (selected_frame == NULL) |
| 1650 | { |
| 1651 | if (message != NULL && !has_stack_frames ()) |
| 1652 | error (("%s"), message); |
| 1653 | /* Hey! Don't trust this. It should really be re-finding the |
| 1654 | last selected frame of the currently selected thread. This, |
| 1655 | though, is better than nothing. */ |
| 1656 | select_frame (get_current_frame ()); |
| 1657 | } |
| 1658 | /* There is always a frame. */ |
| 1659 | gdb_assert (selected_frame != NULL); |
| 1660 | return selected_frame; |
| 1661 | } |
| 1662 | |
| 1663 | /* If there is a selected frame, return it. Otherwise, return NULL. */ |
| 1664 | |
| 1665 | struct frame_info * |
| 1666 | get_selected_frame_if_set (void) |
| 1667 | { |
| 1668 | return selected_frame; |
| 1669 | } |
| 1670 | |
| 1671 | /* This is a variant of get_selected_frame() which can be called when |
| 1672 | the inferior does not have a frame; in that case it will return |
| 1673 | NULL instead of calling error(). */ |
| 1674 | |
| 1675 | struct frame_info * |
| 1676 | deprecated_safe_get_selected_frame (void) |
| 1677 | { |
| 1678 | if (!has_stack_frames ()) |
| 1679 | return NULL; |
| 1680 | return get_selected_frame (NULL); |
| 1681 | } |
| 1682 | |
| 1683 | /* Select frame FI (or NULL - to invalidate the current frame). */ |
| 1684 | |
| 1685 | void |
| 1686 | select_frame (struct frame_info *fi) |
| 1687 | { |
| 1688 | selected_frame = fi; |
| 1689 | /* NOTE: cagney/2002-05-04: FI can be NULL. This occurs when the |
| 1690 | frame is being invalidated. */ |
| 1691 | |
| 1692 | /* FIXME: kseitz/2002-08-28: It would be nice to call |
| 1693 | selected_frame_level_changed_event() right here, but due to limitations |
| 1694 | in the current interfaces, we would end up flooding UIs with events |
| 1695 | because select_frame() is used extensively internally. |
| 1696 | |
| 1697 | Once we have frame-parameterized frame (and frame-related) commands, |
| 1698 | the event notification can be moved here, since this function will only |
| 1699 | be called when the user's selected frame is being changed. */ |
| 1700 | |
| 1701 | /* Ensure that symbols for this frame are read in. Also, determine the |
| 1702 | source language of this frame, and switch to it if desired. */ |
| 1703 | if (fi) |
| 1704 | { |
| 1705 | CORE_ADDR pc; |
| 1706 | |
| 1707 | /* We retrieve the frame's symtab by using the frame PC. |
| 1708 | However we cannot use the frame PC as-is, because it usually |
| 1709 | points to the instruction following the "call", which is |
| 1710 | sometimes the first instruction of another function. So we |
| 1711 | rely on get_frame_address_in_block() which provides us with a |
| 1712 | PC which is guaranteed to be inside the frame's code |
| 1713 | block. */ |
| 1714 | if (get_frame_address_in_block_if_available (fi, &pc)) |
| 1715 | { |
| 1716 | struct compunit_symtab *cust = find_pc_compunit_symtab (pc); |
| 1717 | |
| 1718 | if (cust != NULL |
| 1719 | && compunit_language (cust) != current_language->la_language |
| 1720 | && compunit_language (cust) != language_unknown |
| 1721 | && language_mode == language_mode_auto) |
| 1722 | set_language (compunit_language (cust)); |
| 1723 | } |
| 1724 | } |
| 1725 | } |
| 1726 | |
| 1727 | /* Create an arbitrary (i.e. address specified by user) or innermost frame. |
| 1728 | Always returns a non-NULL value. */ |
| 1729 | |
| 1730 | struct frame_info * |
| 1731 | create_new_frame (CORE_ADDR addr, CORE_ADDR pc) |
| 1732 | { |
| 1733 | struct frame_info *fi; |
| 1734 | |
| 1735 | if (frame_debug) |
| 1736 | { |
| 1737 | fprintf_unfiltered (gdb_stdlog, |
| 1738 | "{ create_new_frame (addr=%s, pc=%s) ", |
| 1739 | hex_string (addr), hex_string (pc)); |
| 1740 | } |
| 1741 | |
| 1742 | fi = FRAME_OBSTACK_ZALLOC (struct frame_info); |
| 1743 | |
| 1744 | fi->next = create_sentinel_frame (current_program_space, |
| 1745 | get_current_regcache ()); |
| 1746 | |
| 1747 | /* Set/update this frame's cached PC value, found in the next frame. |
| 1748 | Do this before looking for this frame's unwinder. A sniffer is |
| 1749 | very likely to read this, and the corresponding unwinder is |
| 1750 | entitled to rely that the PC doesn't magically change. */ |
| 1751 | fi->next->prev_pc.value = pc; |
| 1752 | fi->next->prev_pc.status = CC_VALUE; |
| 1753 | |
| 1754 | /* We currently assume that frame chain's can't cross spaces. */ |
| 1755 | fi->pspace = fi->next->pspace; |
| 1756 | fi->aspace = fi->next->aspace; |
| 1757 | |
| 1758 | /* Select/initialize both the unwind function and the frame's type |
| 1759 | based on the PC. */ |
| 1760 | frame_unwind_find_by_frame (fi, &fi->prologue_cache); |
| 1761 | |
| 1762 | fi->this_id.p = 1; |
| 1763 | fi->this_id.value = frame_id_build (addr, pc); |
| 1764 | |
| 1765 | if (frame_debug) |
| 1766 | { |
| 1767 | fprintf_unfiltered (gdb_stdlog, "-> "); |
| 1768 | fprint_frame (gdb_stdlog, fi); |
| 1769 | fprintf_unfiltered (gdb_stdlog, " }\n"); |
| 1770 | } |
| 1771 | |
| 1772 | return fi; |
| 1773 | } |
| 1774 | |
| 1775 | /* Return the frame that THIS_FRAME calls (NULL if THIS_FRAME is the |
| 1776 | innermost frame). Be careful to not fall off the bottom of the |
| 1777 | frame chain and onto the sentinel frame. */ |
| 1778 | |
| 1779 | struct frame_info * |
| 1780 | get_next_frame (struct frame_info *this_frame) |
| 1781 | { |
| 1782 | if (this_frame->level > 0) |
| 1783 | return this_frame->next; |
| 1784 | else |
| 1785 | return NULL; |
| 1786 | } |
| 1787 | |
| 1788 | /* Return the frame that THIS_FRAME calls. If THIS_FRAME is the |
| 1789 | innermost (i.e. current) frame, return the sentinel frame. Thus, |
| 1790 | unlike get_next_frame(), NULL will never be returned. */ |
| 1791 | |
| 1792 | struct frame_info * |
| 1793 | get_next_frame_sentinel_okay (struct frame_info *this_frame) |
| 1794 | { |
| 1795 | gdb_assert (this_frame != NULL); |
| 1796 | |
| 1797 | /* Note that, due to the manner in which the sentinel frame is |
| 1798 | constructed, this_frame->next still works even when this_frame |
| 1799 | is the sentinel frame. But we disallow it here anyway because |
| 1800 | calling get_next_frame_sentinel_okay() on the sentinel frame |
| 1801 | is likely a coding error. */ |
| 1802 | gdb_assert (this_frame != sentinel_frame); |
| 1803 | |
| 1804 | return this_frame->next; |
| 1805 | } |
| 1806 | |
| 1807 | /* Observer for the target_changed event. */ |
| 1808 | |
| 1809 | static void |
| 1810 | frame_observer_target_changed (struct target_ops *target) |
| 1811 | { |
| 1812 | reinit_frame_cache (); |
| 1813 | } |
| 1814 | |
| 1815 | /* Flush the entire frame cache. */ |
| 1816 | |
| 1817 | void |
| 1818 | reinit_frame_cache (void) |
| 1819 | { |
| 1820 | struct frame_info *fi; |
| 1821 | |
| 1822 | /* Tear down all frame caches. */ |
| 1823 | for (fi = sentinel_frame; fi != NULL; fi = fi->prev) |
| 1824 | { |
| 1825 | if (fi->prologue_cache && fi->unwind->dealloc_cache) |
| 1826 | fi->unwind->dealloc_cache (fi, fi->prologue_cache); |
| 1827 | if (fi->base_cache && fi->base->unwind->dealloc_cache) |
| 1828 | fi->base->unwind->dealloc_cache (fi, fi->base_cache); |
| 1829 | } |
| 1830 | |
| 1831 | /* Since we can't really be sure what the first object allocated was. */ |
| 1832 | obstack_free (&frame_cache_obstack, 0); |
| 1833 | obstack_init (&frame_cache_obstack); |
| 1834 | |
| 1835 | if (sentinel_frame != NULL) |
| 1836 | annotate_frames_invalid (); |
| 1837 | |
| 1838 | sentinel_frame = NULL; /* Invalidate cache */ |
| 1839 | select_frame (NULL); |
| 1840 | frame_stash_invalidate (); |
| 1841 | if (frame_debug) |
| 1842 | fprintf_unfiltered (gdb_stdlog, "{ reinit_frame_cache () }\n"); |
| 1843 | } |
| 1844 | |
| 1845 | /* Find where a register is saved (in memory or another register). |
| 1846 | The result of frame_register_unwind is just where it is saved |
| 1847 | relative to this particular frame. */ |
| 1848 | |
| 1849 | static void |
| 1850 | frame_register_unwind_location (struct frame_info *this_frame, int regnum, |
| 1851 | int *optimizedp, enum lval_type *lvalp, |
| 1852 | CORE_ADDR *addrp, int *realnump) |
| 1853 | { |
| 1854 | gdb_assert (this_frame == NULL || this_frame->level >= 0); |
| 1855 | |
| 1856 | while (this_frame != NULL) |
| 1857 | { |
| 1858 | int unavailable; |
| 1859 | |
| 1860 | frame_register_unwind (this_frame, regnum, optimizedp, &unavailable, |
| 1861 | lvalp, addrp, realnump, NULL); |
| 1862 | |
| 1863 | if (*optimizedp) |
| 1864 | break; |
| 1865 | |
| 1866 | if (*lvalp != lval_register) |
| 1867 | break; |
| 1868 | |
| 1869 | regnum = *realnump; |
| 1870 | this_frame = get_next_frame (this_frame); |
| 1871 | } |
| 1872 | } |
| 1873 | |
| 1874 | /* Get the previous raw frame, and check that it is not identical to |
| 1875 | same other frame frame already in the chain. If it is, there is |
| 1876 | most likely a stack cycle, so we discard it, and mark THIS_FRAME as |
| 1877 | outermost, with UNWIND_SAME_ID stop reason. Unlike the other |
| 1878 | validity tests, that compare THIS_FRAME and the next frame, we do |
| 1879 | this right after creating the previous frame, to avoid ever ending |
| 1880 | up with two frames with the same id in the frame chain. */ |
| 1881 | |
| 1882 | static struct frame_info * |
| 1883 | get_prev_frame_if_no_cycle (struct frame_info *this_frame) |
| 1884 | { |
| 1885 | struct frame_info *prev_frame; |
| 1886 | |
| 1887 | prev_frame = get_prev_frame_raw (this_frame); |
| 1888 | |
| 1889 | /* Don't compute the frame id of the current frame yet. Unwinding |
| 1890 | the sentinel frame can fail (e.g., if the thread is gone and we |
| 1891 | can't thus read its registers). If we let the cycle detection |
| 1892 | code below try to compute a frame ID, then an error thrown from |
| 1893 | within the frame ID computation would result in the sentinel |
| 1894 | frame as outermost frame, which is bogus. Instead, we'll compute |
| 1895 | the current frame's ID lazily in get_frame_id. Note that there's |
| 1896 | no point in doing cycle detection when there's only one frame, so |
| 1897 | nothing is lost here. */ |
| 1898 | if (prev_frame->level == 0) |
| 1899 | return prev_frame; |
| 1900 | |
| 1901 | try |
| 1902 | { |
| 1903 | compute_frame_id (prev_frame); |
| 1904 | if (!frame_stash_add (prev_frame)) |
| 1905 | { |
| 1906 | /* Another frame with the same id was already in the stash. We just |
| 1907 | detected a cycle. */ |
| 1908 | if (frame_debug) |
| 1909 | { |
| 1910 | fprintf_unfiltered (gdb_stdlog, "-> "); |
| 1911 | fprint_frame (gdb_stdlog, NULL); |
| 1912 | fprintf_unfiltered (gdb_stdlog, " // this frame has same ID }\n"); |
| 1913 | } |
| 1914 | this_frame->stop_reason = UNWIND_SAME_ID; |
| 1915 | /* Unlink. */ |
| 1916 | prev_frame->next = NULL; |
| 1917 | this_frame->prev = NULL; |
| 1918 | prev_frame = NULL; |
| 1919 | } |
| 1920 | } |
| 1921 | catch (const gdb_exception &ex) |
| 1922 | { |
| 1923 | prev_frame->next = NULL; |
| 1924 | this_frame->prev = NULL; |
| 1925 | |
| 1926 | throw; |
| 1927 | } |
| 1928 | |
| 1929 | return prev_frame; |
| 1930 | } |
| 1931 | |
| 1932 | /* Helper function for get_prev_frame_always, this is called inside a |
| 1933 | TRY_CATCH block. Return the frame that called THIS_FRAME or NULL if |
| 1934 | there is no such frame. This may throw an exception. */ |
| 1935 | |
| 1936 | static struct frame_info * |
| 1937 | get_prev_frame_always_1 (struct frame_info *this_frame) |
| 1938 | { |
| 1939 | struct gdbarch *gdbarch; |
| 1940 | |
| 1941 | gdb_assert (this_frame != NULL); |
| 1942 | gdbarch = get_frame_arch (this_frame); |
| 1943 | |
| 1944 | if (frame_debug) |
| 1945 | { |
| 1946 | fprintf_unfiltered (gdb_stdlog, "{ get_prev_frame_always (this_frame="); |
| 1947 | if (this_frame != NULL) |
| 1948 | fprintf_unfiltered (gdb_stdlog, "%d", this_frame->level); |
| 1949 | else |
| 1950 | fprintf_unfiltered (gdb_stdlog, "<NULL>"); |
| 1951 | fprintf_unfiltered (gdb_stdlog, ") "); |
| 1952 | } |
| 1953 | |
| 1954 | /* Only try to do the unwind once. */ |
| 1955 | if (this_frame->prev_p) |
| 1956 | { |
| 1957 | if (frame_debug) |
| 1958 | { |
| 1959 | fprintf_unfiltered (gdb_stdlog, "-> "); |
| 1960 | fprint_frame (gdb_stdlog, this_frame->prev); |
| 1961 | fprintf_unfiltered (gdb_stdlog, " // cached \n"); |
| 1962 | } |
| 1963 | return this_frame->prev; |
| 1964 | } |
| 1965 | |
| 1966 | /* If the frame unwinder hasn't been selected yet, we must do so |
| 1967 | before setting prev_p; otherwise the check for misbehaved |
| 1968 | sniffers will think that this frame's sniffer tried to unwind |
| 1969 | further (see frame_cleanup_after_sniffer). */ |
| 1970 | if (this_frame->unwind == NULL) |
| 1971 | frame_unwind_find_by_frame (this_frame, &this_frame->prologue_cache); |
| 1972 | |
| 1973 | this_frame->prev_p = 1; |
| 1974 | this_frame->stop_reason = UNWIND_NO_REASON; |
| 1975 | |
| 1976 | /* If we are unwinding from an inline frame, all of the below tests |
| 1977 | were already performed when we unwound from the next non-inline |
| 1978 | frame. We must skip them, since we can not get THIS_FRAME's ID |
| 1979 | until we have unwound all the way down to the previous non-inline |
| 1980 | frame. */ |
| 1981 | if (get_frame_type (this_frame) == INLINE_FRAME) |
| 1982 | return get_prev_frame_if_no_cycle (this_frame); |
| 1983 | |
| 1984 | /* Check that this frame is unwindable. If it isn't, don't try to |
| 1985 | unwind to the prev frame. */ |
| 1986 | this_frame->stop_reason |
| 1987 | = this_frame->unwind->stop_reason (this_frame, |
| 1988 | &this_frame->prologue_cache); |
| 1989 | |
| 1990 | if (this_frame->stop_reason != UNWIND_NO_REASON) |
| 1991 | { |
| 1992 | if (frame_debug) |
| 1993 | { |
| 1994 | enum unwind_stop_reason reason = this_frame->stop_reason; |
| 1995 | |
| 1996 | fprintf_unfiltered (gdb_stdlog, "-> "); |
| 1997 | fprint_frame (gdb_stdlog, NULL); |
| 1998 | fprintf_unfiltered (gdb_stdlog, " // %s }\n", |
| 1999 | frame_stop_reason_symbol_string (reason)); |
| 2000 | } |
| 2001 | return NULL; |
| 2002 | } |
| 2003 | |
| 2004 | /* Check that this frame's ID isn't inner to (younger, below, next) |
| 2005 | the next frame. This happens when a frame unwind goes backwards. |
| 2006 | This check is valid only if this frame and the next frame are NORMAL. |
| 2007 | See the comment at frame_id_inner for details. */ |
| 2008 | if (get_frame_type (this_frame) == NORMAL_FRAME |
| 2009 | && this_frame->next->unwind->type == NORMAL_FRAME |
| 2010 | && frame_id_inner (get_frame_arch (this_frame->next), |
| 2011 | get_frame_id (this_frame), |
| 2012 | get_frame_id (this_frame->next))) |
| 2013 | { |
| 2014 | CORE_ADDR this_pc_in_block; |
| 2015 | struct minimal_symbol *morestack_msym; |
| 2016 | const char *morestack_name = NULL; |
| 2017 | |
| 2018 | /* gcc -fsplit-stack __morestack can continue the stack anywhere. */ |
| 2019 | this_pc_in_block = get_frame_address_in_block (this_frame); |
| 2020 | morestack_msym = lookup_minimal_symbol_by_pc (this_pc_in_block).minsym; |
| 2021 | if (morestack_msym) |
| 2022 | morestack_name = MSYMBOL_LINKAGE_NAME (morestack_msym); |
| 2023 | if (!morestack_name || strcmp (morestack_name, "__morestack") != 0) |
| 2024 | { |
| 2025 | if (frame_debug) |
| 2026 | { |
| 2027 | fprintf_unfiltered (gdb_stdlog, "-> "); |
| 2028 | fprint_frame (gdb_stdlog, NULL); |
| 2029 | fprintf_unfiltered (gdb_stdlog, |
| 2030 | " // this frame ID is inner }\n"); |
| 2031 | } |
| 2032 | this_frame->stop_reason = UNWIND_INNER_ID; |
| 2033 | return NULL; |
| 2034 | } |
| 2035 | } |
| 2036 | |
| 2037 | /* Check that this and the next frame do not unwind the PC register |
| 2038 | to the same memory location. If they do, then even though they |
| 2039 | have different frame IDs, the new frame will be bogus; two |
| 2040 | functions can't share a register save slot for the PC. This can |
| 2041 | happen when the prologue analyzer finds a stack adjustment, but |
| 2042 | no PC save. |
| 2043 | |
| 2044 | This check does assume that the "PC register" is roughly a |
| 2045 | traditional PC, even if the gdbarch_unwind_pc method adjusts |
| 2046 | it (we do not rely on the value, only on the unwound PC being |
| 2047 | dependent on this value). A potential improvement would be |
| 2048 | to have the frame prev_pc method and the gdbarch unwind_pc |
| 2049 | method set the same lval and location information as |
| 2050 | frame_register_unwind. */ |
| 2051 | if (this_frame->level > 0 |
| 2052 | && gdbarch_pc_regnum (gdbarch) >= 0 |
| 2053 | && get_frame_type (this_frame) == NORMAL_FRAME |
| 2054 | && (get_frame_type (this_frame->next) == NORMAL_FRAME |
| 2055 | || get_frame_type (this_frame->next) == INLINE_FRAME)) |
| 2056 | { |
| 2057 | int optimized, realnum, nrealnum; |
| 2058 | enum lval_type lval, nlval; |
| 2059 | CORE_ADDR addr, naddr; |
| 2060 | |
| 2061 | frame_register_unwind_location (this_frame, |
| 2062 | gdbarch_pc_regnum (gdbarch), |
| 2063 | &optimized, &lval, &addr, &realnum); |
| 2064 | frame_register_unwind_location (get_next_frame (this_frame), |
| 2065 | gdbarch_pc_regnum (gdbarch), |
| 2066 | &optimized, &nlval, &naddr, &nrealnum); |
| 2067 | |
| 2068 | if ((lval == lval_memory && lval == nlval && addr == naddr) |
| 2069 | || (lval == lval_register && lval == nlval && realnum == nrealnum)) |
| 2070 | { |
| 2071 | if (frame_debug) |
| 2072 | { |
| 2073 | fprintf_unfiltered (gdb_stdlog, "-> "); |
| 2074 | fprint_frame (gdb_stdlog, NULL); |
| 2075 | fprintf_unfiltered (gdb_stdlog, " // no saved PC }\n"); |
| 2076 | } |
| 2077 | |
| 2078 | this_frame->stop_reason = UNWIND_NO_SAVED_PC; |
| 2079 | this_frame->prev = NULL; |
| 2080 | return NULL; |
| 2081 | } |
| 2082 | } |
| 2083 | |
| 2084 | return get_prev_frame_if_no_cycle (this_frame); |
| 2085 | } |
| 2086 | |
| 2087 | /* Return a "struct frame_info" corresponding to the frame that called |
| 2088 | THIS_FRAME. Returns NULL if there is no such frame. |
| 2089 | |
| 2090 | Unlike get_prev_frame, this function always tries to unwind the |
| 2091 | frame. */ |
| 2092 | |
| 2093 | struct frame_info * |
| 2094 | get_prev_frame_always (struct frame_info *this_frame) |
| 2095 | { |
| 2096 | struct frame_info *prev_frame = NULL; |
| 2097 | |
| 2098 | try |
| 2099 | { |
| 2100 | prev_frame = get_prev_frame_always_1 (this_frame); |
| 2101 | } |
| 2102 | catch (const gdb_exception_error &ex) |
| 2103 | { |
| 2104 | if (ex.error == MEMORY_ERROR) |
| 2105 | { |
| 2106 | this_frame->stop_reason = UNWIND_MEMORY_ERROR; |
| 2107 | if (ex.message != NULL) |
| 2108 | { |
| 2109 | char *stop_string; |
| 2110 | size_t size; |
| 2111 | |
| 2112 | /* The error needs to live as long as the frame does. |
| 2113 | Allocate using stack local STOP_STRING then assign the |
| 2114 | pointer to the frame, this allows the STOP_STRING on the |
| 2115 | frame to be of type 'const char *'. */ |
| 2116 | size = ex.message->size () + 1; |
| 2117 | stop_string = (char *) frame_obstack_zalloc (size); |
| 2118 | memcpy (stop_string, ex.what (), size); |
| 2119 | this_frame->stop_string = stop_string; |
| 2120 | } |
| 2121 | prev_frame = NULL; |
| 2122 | } |
| 2123 | else |
| 2124 | throw; |
| 2125 | } |
| 2126 | |
| 2127 | return prev_frame; |
| 2128 | } |
| 2129 | |
| 2130 | /* Construct a new "struct frame_info" and link it previous to |
| 2131 | this_frame. */ |
| 2132 | |
| 2133 | static struct frame_info * |
| 2134 | get_prev_frame_raw (struct frame_info *this_frame) |
| 2135 | { |
| 2136 | struct frame_info *prev_frame; |
| 2137 | |
| 2138 | /* Allocate the new frame but do not wire it in to the frame chain. |
| 2139 | Some (bad) code in INIT_FRAME_EXTRA_INFO tries to look along |
| 2140 | frame->next to pull some fancy tricks (of course such code is, by |
| 2141 | definition, recursive). Try to prevent it. |
| 2142 | |
| 2143 | There is no reason to worry about memory leaks, should the |
| 2144 | remainder of the function fail. The allocated memory will be |
| 2145 | quickly reclaimed when the frame cache is flushed, and the `we've |
| 2146 | been here before' check above will stop repeated memory |
| 2147 | allocation calls. */ |
| 2148 | prev_frame = FRAME_OBSTACK_ZALLOC (struct frame_info); |
| 2149 | prev_frame->level = this_frame->level + 1; |
| 2150 | |
| 2151 | /* For now, assume we don't have frame chains crossing address |
| 2152 | spaces. */ |
| 2153 | prev_frame->pspace = this_frame->pspace; |
| 2154 | prev_frame->aspace = this_frame->aspace; |
| 2155 | |
| 2156 | /* Don't yet compute ->unwind (and hence ->type). It is computed |
| 2157 | on-demand in get_frame_type, frame_register_unwind, and |
| 2158 | get_frame_id. */ |
| 2159 | |
| 2160 | /* Don't yet compute the frame's ID. It is computed on-demand by |
| 2161 | get_frame_id(). */ |
| 2162 | |
| 2163 | /* The unwound frame ID is validate at the start of this function, |
| 2164 | as part of the logic to decide if that frame should be further |
| 2165 | unwound, and not here while the prev frame is being created. |
| 2166 | Doing this makes it possible for the user to examine a frame that |
| 2167 | has an invalid frame ID. |
| 2168 | |
| 2169 | Some very old VAX code noted: [...] For the sake of argument, |
| 2170 | suppose that the stack is somewhat trashed (which is one reason |
| 2171 | that "info frame" exists). So, return 0 (indicating we don't |
| 2172 | know the address of the arglist) if we don't know what frame this |
| 2173 | frame calls. */ |
| 2174 | |
| 2175 | /* Link it in. */ |
| 2176 | this_frame->prev = prev_frame; |
| 2177 | prev_frame->next = this_frame; |
| 2178 | |
| 2179 | if (frame_debug) |
| 2180 | { |
| 2181 | fprintf_unfiltered (gdb_stdlog, "-> "); |
| 2182 | fprint_frame (gdb_stdlog, prev_frame); |
| 2183 | fprintf_unfiltered (gdb_stdlog, " }\n"); |
| 2184 | } |
| 2185 | |
| 2186 | return prev_frame; |
| 2187 | } |
| 2188 | |
| 2189 | /* Debug routine to print a NULL frame being returned. */ |
| 2190 | |
| 2191 | static void |
| 2192 | frame_debug_got_null_frame (struct frame_info *this_frame, |
| 2193 | const char *reason) |
| 2194 | { |
| 2195 | if (frame_debug) |
| 2196 | { |
| 2197 | fprintf_unfiltered (gdb_stdlog, "{ get_prev_frame (this_frame="); |
| 2198 | if (this_frame != NULL) |
| 2199 | fprintf_unfiltered (gdb_stdlog, "%d", this_frame->level); |
| 2200 | else |
| 2201 | fprintf_unfiltered (gdb_stdlog, "<NULL>"); |
| 2202 | fprintf_unfiltered (gdb_stdlog, ") -> // %s}\n", reason); |
| 2203 | } |
| 2204 | } |
| 2205 | |
| 2206 | /* Is this (non-sentinel) frame in the "main"() function? */ |
| 2207 | |
| 2208 | static int |
| 2209 | inside_main_func (struct frame_info *this_frame) |
| 2210 | { |
| 2211 | struct bound_minimal_symbol msymbol; |
| 2212 | CORE_ADDR maddr; |
| 2213 | |
| 2214 | if (symfile_objfile == 0) |
| 2215 | return 0; |
| 2216 | msymbol = lookup_minimal_symbol (main_name (), NULL, symfile_objfile); |
| 2217 | if (msymbol.minsym == NULL) |
| 2218 | return 0; |
| 2219 | /* Make certain that the code, and not descriptor, address is |
| 2220 | returned. */ |
| 2221 | maddr = gdbarch_convert_from_func_ptr_addr (get_frame_arch (this_frame), |
| 2222 | BMSYMBOL_VALUE_ADDRESS (msymbol), |
| 2223 | current_top_target ()); |
| 2224 | return maddr == get_frame_func (this_frame); |
| 2225 | } |
| 2226 | |
| 2227 | /* Test whether THIS_FRAME is inside the process entry point function. */ |
| 2228 | |
| 2229 | static int |
| 2230 | inside_entry_func (struct frame_info *this_frame) |
| 2231 | { |
| 2232 | CORE_ADDR entry_point; |
| 2233 | |
| 2234 | if (!entry_point_address_query (&entry_point)) |
| 2235 | return 0; |
| 2236 | |
| 2237 | return get_frame_func (this_frame) == entry_point; |
| 2238 | } |
| 2239 | |
| 2240 | /* Return a structure containing various interesting information about |
| 2241 | the frame that called THIS_FRAME. Returns NULL if there is entier |
| 2242 | no such frame or the frame fails any of a set of target-independent |
| 2243 | condition that should terminate the frame chain (e.g., as unwinding |
| 2244 | past main()). |
| 2245 | |
| 2246 | This function should not contain target-dependent tests, such as |
| 2247 | checking whether the program-counter is zero. */ |
| 2248 | |
| 2249 | struct frame_info * |
| 2250 | get_prev_frame (struct frame_info *this_frame) |
| 2251 | { |
| 2252 | CORE_ADDR frame_pc; |
| 2253 | int frame_pc_p; |
| 2254 | |
| 2255 | /* There is always a frame. If this assertion fails, suspect that |
| 2256 | something should be calling get_selected_frame() or |
| 2257 | get_current_frame(). */ |
| 2258 | gdb_assert (this_frame != NULL); |
| 2259 | |
| 2260 | /* If this_frame is the current frame, then compute and stash |
| 2261 | its frame id prior to fetching and computing the frame id of the |
| 2262 | previous frame. Otherwise, the cycle detection code in |
| 2263 | get_prev_frame_if_no_cycle() will not work correctly. When |
| 2264 | get_frame_id() is called later on, an assertion error will |
| 2265 | be triggered in the event of a cycle between the current |
| 2266 | frame and its previous frame. */ |
| 2267 | if (this_frame->level == 0) |
| 2268 | get_frame_id (this_frame); |
| 2269 | |
| 2270 | frame_pc_p = get_frame_pc_if_available (this_frame, &frame_pc); |
| 2271 | |
| 2272 | /* tausq/2004-12-07: Dummy frames are skipped because it doesn't make much |
| 2273 | sense to stop unwinding at a dummy frame. One place where a dummy |
| 2274 | frame may have an address "inside_main_func" is on HPUX. On HPUX, the |
| 2275 | pcsqh register (space register for the instruction at the head of the |
| 2276 | instruction queue) cannot be written directly; the only way to set it |
| 2277 | is to branch to code that is in the target space. In order to implement |
| 2278 | frame dummies on HPUX, the called function is made to jump back to where |
| 2279 | the inferior was when the user function was called. If gdb was inside |
| 2280 | the main function when we created the dummy frame, the dummy frame will |
| 2281 | point inside the main function. */ |
| 2282 | if (this_frame->level >= 0 |
| 2283 | && get_frame_type (this_frame) == NORMAL_FRAME |
| 2284 | && !user_set_backtrace_options.backtrace_past_main |
| 2285 | && frame_pc_p |
| 2286 | && inside_main_func (this_frame)) |
| 2287 | /* Don't unwind past main(). Note, this is done _before_ the |
| 2288 | frame has been marked as previously unwound. That way if the |
| 2289 | user later decides to enable unwinds past main(), that will |
| 2290 | automatically happen. */ |
| 2291 | { |
| 2292 | frame_debug_got_null_frame (this_frame, "inside main func"); |
| 2293 | return NULL; |
| 2294 | } |
| 2295 | |
| 2296 | /* If the user's backtrace limit has been exceeded, stop. We must |
| 2297 | add two to the current level; one of those accounts for backtrace_limit |
| 2298 | being 1-based and the level being 0-based, and the other accounts for |
| 2299 | the level of the new frame instead of the level of the current |
| 2300 | frame. */ |
| 2301 | if (this_frame->level + 2 > user_set_backtrace_options.backtrace_limit) |
| 2302 | { |
| 2303 | frame_debug_got_null_frame (this_frame, "backtrace limit exceeded"); |
| 2304 | return NULL; |
| 2305 | } |
| 2306 | |
| 2307 | /* If we're already inside the entry function for the main objfile, |
| 2308 | then it isn't valid. Don't apply this test to a dummy frame - |
| 2309 | dummy frame PCs typically land in the entry func. Don't apply |
| 2310 | this test to the sentinel frame. Sentinel frames should always |
| 2311 | be allowed to unwind. */ |
| 2312 | /* NOTE: cagney/2003-07-07: Fixed a bug in inside_main_func() - |
| 2313 | wasn't checking for "main" in the minimal symbols. With that |
| 2314 | fixed asm-source tests now stop in "main" instead of halting the |
| 2315 | backtrace in weird and wonderful ways somewhere inside the entry |
| 2316 | file. Suspect that tests for inside the entry file/func were |
| 2317 | added to work around that (now fixed) case. */ |
| 2318 | /* NOTE: cagney/2003-07-15: danielj (if I'm reading it right) |
| 2319 | suggested having the inside_entry_func test use the |
| 2320 | inside_main_func() msymbol trick (along with entry_point_address() |
| 2321 | I guess) to determine the address range of the start function. |
| 2322 | That should provide a far better stopper than the current |
| 2323 | heuristics. */ |
| 2324 | /* NOTE: tausq/2004-10-09: this is needed if, for example, the compiler |
| 2325 | applied tail-call optimizations to main so that a function called |
| 2326 | from main returns directly to the caller of main. Since we don't |
| 2327 | stop at main, we should at least stop at the entry point of the |
| 2328 | application. */ |
| 2329 | if (this_frame->level >= 0 |
| 2330 | && get_frame_type (this_frame) == NORMAL_FRAME |
| 2331 | && !user_set_backtrace_options.backtrace_past_entry |
| 2332 | && frame_pc_p |
| 2333 | && inside_entry_func (this_frame)) |
| 2334 | { |
| 2335 | frame_debug_got_null_frame (this_frame, "inside entry func"); |
| 2336 | return NULL; |
| 2337 | } |
| 2338 | |
| 2339 | /* Assume that the only way to get a zero PC is through something |
| 2340 | like a SIGSEGV or a dummy frame, and hence that NORMAL frames |
| 2341 | will never unwind a zero PC. */ |
| 2342 | if (this_frame->level > 0 |
| 2343 | && (get_frame_type (this_frame) == NORMAL_FRAME |
| 2344 | || get_frame_type (this_frame) == INLINE_FRAME) |
| 2345 | && get_frame_type (get_next_frame (this_frame)) == NORMAL_FRAME |
| 2346 | && frame_pc_p && frame_pc == 0) |
| 2347 | { |
| 2348 | frame_debug_got_null_frame (this_frame, "zero PC"); |
| 2349 | return NULL; |
| 2350 | } |
| 2351 | |
| 2352 | return get_prev_frame_always (this_frame); |
| 2353 | } |
| 2354 | |
| 2355 | struct frame_id |
| 2356 | get_prev_frame_id_by_id (struct frame_id id) |
| 2357 | { |
| 2358 | struct frame_id prev_id; |
| 2359 | struct frame_info *frame; |
| 2360 | |
| 2361 | frame = frame_find_by_id (id); |
| 2362 | |
| 2363 | if (frame != NULL) |
| 2364 | prev_id = get_frame_id (get_prev_frame (frame)); |
| 2365 | else |
| 2366 | prev_id = null_frame_id; |
| 2367 | |
| 2368 | return prev_id; |
| 2369 | } |
| 2370 | |
| 2371 | CORE_ADDR |
| 2372 | get_frame_pc (struct frame_info *frame) |
| 2373 | { |
| 2374 | gdb_assert (frame->next != NULL); |
| 2375 | return frame_unwind_pc (frame->next); |
| 2376 | } |
| 2377 | |
| 2378 | int |
| 2379 | get_frame_pc_if_available (struct frame_info *frame, CORE_ADDR *pc) |
| 2380 | { |
| 2381 | |
| 2382 | gdb_assert (frame->next != NULL); |
| 2383 | |
| 2384 | try |
| 2385 | { |
| 2386 | *pc = frame_unwind_pc (frame->next); |
| 2387 | } |
| 2388 | catch (const gdb_exception_error &ex) |
| 2389 | { |
| 2390 | if (ex.error == NOT_AVAILABLE_ERROR) |
| 2391 | return 0; |
| 2392 | else |
| 2393 | throw; |
| 2394 | } |
| 2395 | |
| 2396 | return 1; |
| 2397 | } |
| 2398 | |
| 2399 | /* Return an address that falls within THIS_FRAME's code block. */ |
| 2400 | |
| 2401 | CORE_ADDR |
| 2402 | get_frame_address_in_block (struct frame_info *this_frame) |
| 2403 | { |
| 2404 | /* A draft address. */ |
| 2405 | CORE_ADDR pc = get_frame_pc (this_frame); |
| 2406 | |
| 2407 | struct frame_info *next_frame = this_frame->next; |
| 2408 | |
| 2409 | /* Calling get_frame_pc returns the resume address for THIS_FRAME. |
| 2410 | Normally the resume address is inside the body of the function |
| 2411 | associated with THIS_FRAME, but there is a special case: when |
| 2412 | calling a function which the compiler knows will never return |
| 2413 | (for instance abort), the call may be the very last instruction |
| 2414 | in the calling function. The resume address will point after the |
| 2415 | call and may be at the beginning of a different function |
| 2416 | entirely. |
| 2417 | |
| 2418 | If THIS_FRAME is a signal frame or dummy frame, then we should |
| 2419 | not adjust the unwound PC. For a dummy frame, GDB pushed the |
| 2420 | resume address manually onto the stack. For a signal frame, the |
| 2421 | OS may have pushed the resume address manually and invoked the |
| 2422 | handler (e.g. GNU/Linux), or invoked the trampoline which called |
| 2423 | the signal handler - but in either case the signal handler is |
| 2424 | expected to return to the trampoline. So in both of these |
| 2425 | cases we know that the resume address is executable and |
| 2426 | related. So we only need to adjust the PC if THIS_FRAME |
| 2427 | is a normal function. |
| 2428 | |
| 2429 | If the program has been interrupted while THIS_FRAME is current, |
| 2430 | then clearly the resume address is inside the associated |
| 2431 | function. There are three kinds of interruption: debugger stop |
| 2432 | (next frame will be SENTINEL_FRAME), operating system |
| 2433 | signal or exception (next frame will be SIGTRAMP_FRAME), |
| 2434 | or debugger-induced function call (next frame will be |
| 2435 | DUMMY_FRAME). So we only need to adjust the PC if |
| 2436 | NEXT_FRAME is a normal function. |
| 2437 | |
| 2438 | We check the type of NEXT_FRAME first, since it is already |
| 2439 | known; frame type is determined by the unwinder, and since |
| 2440 | we have THIS_FRAME we've already selected an unwinder for |
| 2441 | NEXT_FRAME. |
| 2442 | |
| 2443 | If the next frame is inlined, we need to keep going until we find |
| 2444 | the real function - for instance, if a signal handler is invoked |
| 2445 | while in an inlined function, then the code address of the |
| 2446 | "calling" normal function should not be adjusted either. */ |
| 2447 | |
| 2448 | while (get_frame_type (next_frame) == INLINE_FRAME) |
| 2449 | next_frame = next_frame->next; |
| 2450 | |
| 2451 | if ((get_frame_type (next_frame) == NORMAL_FRAME |
| 2452 | || get_frame_type (next_frame) == TAILCALL_FRAME) |
| 2453 | && (get_frame_type (this_frame) == NORMAL_FRAME |
| 2454 | || get_frame_type (this_frame) == TAILCALL_FRAME |
| 2455 | || get_frame_type (this_frame) == INLINE_FRAME)) |
| 2456 | return pc - 1; |
| 2457 | |
| 2458 | return pc; |
| 2459 | } |
| 2460 | |
| 2461 | int |
| 2462 | get_frame_address_in_block_if_available (struct frame_info *this_frame, |
| 2463 | CORE_ADDR *pc) |
| 2464 | { |
| 2465 | |
| 2466 | try |
| 2467 | { |
| 2468 | *pc = get_frame_address_in_block (this_frame); |
| 2469 | } |
| 2470 | catch (const gdb_exception_error &ex) |
| 2471 | { |
| 2472 | if (ex.error == NOT_AVAILABLE_ERROR) |
| 2473 | return 0; |
| 2474 | throw; |
| 2475 | } |
| 2476 | |
| 2477 | return 1; |
| 2478 | } |
| 2479 | |
| 2480 | symtab_and_line |
| 2481 | find_frame_sal (frame_info *frame) |
| 2482 | { |
| 2483 | struct frame_info *next_frame; |
| 2484 | int notcurrent; |
| 2485 | CORE_ADDR pc; |
| 2486 | |
| 2487 | /* If the next frame represents an inlined function call, this frame's |
| 2488 | sal is the "call site" of that inlined function, which can not |
| 2489 | be inferred from get_frame_pc. */ |
| 2490 | next_frame = get_next_frame (frame); |
| 2491 | if (frame_inlined_callees (frame) > 0) |
| 2492 | { |
| 2493 | struct symbol *sym; |
| 2494 | |
| 2495 | if (next_frame) |
| 2496 | sym = get_frame_function (next_frame); |
| 2497 | else |
| 2498 | sym = inline_skipped_symbol (inferior_thread ()); |
| 2499 | |
| 2500 | /* If frame is inline, it certainly has symbols. */ |
| 2501 | gdb_assert (sym); |
| 2502 | |
| 2503 | symtab_and_line sal; |
| 2504 | if (SYMBOL_LINE (sym) != 0) |
| 2505 | { |
| 2506 | sal.symtab = symbol_symtab (sym); |
| 2507 | sal.line = SYMBOL_LINE (sym); |
| 2508 | } |
| 2509 | else |
| 2510 | /* If the symbol does not have a location, we don't know where |
| 2511 | the call site is. Do not pretend to. This is jarring, but |
| 2512 | we can't do much better. */ |
| 2513 | sal.pc = get_frame_pc (frame); |
| 2514 | |
| 2515 | sal.pspace = get_frame_program_space (frame); |
| 2516 | return sal; |
| 2517 | } |
| 2518 | |
| 2519 | /* If FRAME is not the innermost frame, that normally means that |
| 2520 | FRAME->pc points at the return instruction (which is *after* the |
| 2521 | call instruction), and we want to get the line containing the |
| 2522 | call (because the call is where the user thinks the program is). |
| 2523 | However, if the next frame is either a SIGTRAMP_FRAME or a |
| 2524 | DUMMY_FRAME, then the next frame will contain a saved interrupt |
| 2525 | PC and such a PC indicates the current (rather than next) |
| 2526 | instruction/line, consequently, for such cases, want to get the |
| 2527 | line containing fi->pc. */ |
| 2528 | if (!get_frame_pc_if_available (frame, &pc)) |
| 2529 | return {}; |
| 2530 | |
| 2531 | notcurrent = (pc != get_frame_address_in_block (frame)); |
| 2532 | return find_pc_line (pc, notcurrent); |
| 2533 | } |
| 2534 | |
| 2535 | /* Per "frame.h", return the ``address'' of the frame. Code should |
| 2536 | really be using get_frame_id(). */ |
| 2537 | CORE_ADDR |
| 2538 | get_frame_base (struct frame_info *fi) |
| 2539 | { |
| 2540 | return get_frame_id (fi).stack_addr; |
| 2541 | } |
| 2542 | |
| 2543 | /* High-level offsets into the frame. Used by the debug info. */ |
| 2544 | |
| 2545 | CORE_ADDR |
| 2546 | get_frame_base_address (struct frame_info *fi) |
| 2547 | { |
| 2548 | if (get_frame_type (fi) != NORMAL_FRAME) |
| 2549 | return 0; |
| 2550 | if (fi->base == NULL) |
| 2551 | fi->base = frame_base_find_by_frame (fi); |
| 2552 | /* Sneaky: If the low-level unwind and high-level base code share a |
| 2553 | common unwinder, let them share the prologue cache. */ |
| 2554 | if (fi->base->unwind == fi->unwind) |
| 2555 | return fi->base->this_base (fi, &fi->prologue_cache); |
| 2556 | return fi->base->this_base (fi, &fi->base_cache); |
| 2557 | } |
| 2558 | |
| 2559 | CORE_ADDR |
| 2560 | get_frame_locals_address (struct frame_info *fi) |
| 2561 | { |
| 2562 | if (get_frame_type (fi) != NORMAL_FRAME) |
| 2563 | return 0; |
| 2564 | /* If there isn't a frame address method, find it. */ |
| 2565 | if (fi->base == NULL) |
| 2566 | fi->base = frame_base_find_by_frame (fi); |
| 2567 | /* Sneaky: If the low-level unwind and high-level base code share a |
| 2568 | common unwinder, let them share the prologue cache. */ |
| 2569 | if (fi->base->unwind == fi->unwind) |
| 2570 | return fi->base->this_locals (fi, &fi->prologue_cache); |
| 2571 | return fi->base->this_locals (fi, &fi->base_cache); |
| 2572 | } |
| 2573 | |
| 2574 | CORE_ADDR |
| 2575 | get_frame_args_address (struct frame_info *fi) |
| 2576 | { |
| 2577 | if (get_frame_type (fi) != NORMAL_FRAME) |
| 2578 | return 0; |
| 2579 | /* If there isn't a frame address method, find it. */ |
| 2580 | if (fi->base == NULL) |
| 2581 | fi->base = frame_base_find_by_frame (fi); |
| 2582 | /* Sneaky: If the low-level unwind and high-level base code share a |
| 2583 | common unwinder, let them share the prologue cache. */ |
| 2584 | if (fi->base->unwind == fi->unwind) |
| 2585 | return fi->base->this_args (fi, &fi->prologue_cache); |
| 2586 | return fi->base->this_args (fi, &fi->base_cache); |
| 2587 | } |
| 2588 | |
| 2589 | /* Return true if the frame unwinder for frame FI is UNWINDER; false |
| 2590 | otherwise. */ |
| 2591 | |
| 2592 | int |
| 2593 | frame_unwinder_is (struct frame_info *fi, const struct frame_unwind *unwinder) |
| 2594 | { |
| 2595 | if (fi->unwind == NULL) |
| 2596 | frame_unwind_find_by_frame (fi, &fi->prologue_cache); |
| 2597 | return fi->unwind == unwinder; |
| 2598 | } |
| 2599 | |
| 2600 | /* Level of the selected frame: 0 for innermost, 1 for its caller, ... |
| 2601 | or -1 for a NULL frame. */ |
| 2602 | |
| 2603 | int |
| 2604 | frame_relative_level (struct frame_info *fi) |
| 2605 | { |
| 2606 | if (fi == NULL) |
| 2607 | return -1; |
| 2608 | else |
| 2609 | return fi->level; |
| 2610 | } |
| 2611 | |
| 2612 | enum frame_type |
| 2613 | get_frame_type (struct frame_info *frame) |
| 2614 | { |
| 2615 | if (frame->unwind == NULL) |
| 2616 | /* Initialize the frame's unwinder because that's what |
| 2617 | provides the frame's type. */ |
| 2618 | frame_unwind_find_by_frame (frame, &frame->prologue_cache); |
| 2619 | return frame->unwind->type; |
| 2620 | } |
| 2621 | |
| 2622 | struct program_space * |
| 2623 | get_frame_program_space (struct frame_info *frame) |
| 2624 | { |
| 2625 | return frame->pspace; |
| 2626 | } |
| 2627 | |
| 2628 | struct program_space * |
| 2629 | frame_unwind_program_space (struct frame_info *this_frame) |
| 2630 | { |
| 2631 | gdb_assert (this_frame); |
| 2632 | |
| 2633 | /* This is really a placeholder to keep the API consistent --- we |
| 2634 | assume for now that we don't have frame chains crossing |
| 2635 | spaces. */ |
| 2636 | return this_frame->pspace; |
| 2637 | } |
| 2638 | |
| 2639 | const address_space * |
| 2640 | get_frame_address_space (struct frame_info *frame) |
| 2641 | { |
| 2642 | return frame->aspace; |
| 2643 | } |
| 2644 | |
| 2645 | /* Memory access methods. */ |
| 2646 | |
| 2647 | void |
| 2648 | get_frame_memory (struct frame_info *this_frame, CORE_ADDR addr, |
| 2649 | gdb_byte *buf, int len) |
| 2650 | { |
| 2651 | read_memory (addr, buf, len); |
| 2652 | } |
| 2653 | |
| 2654 | LONGEST |
| 2655 | get_frame_memory_signed (struct frame_info *this_frame, CORE_ADDR addr, |
| 2656 | int len) |
| 2657 | { |
| 2658 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
| 2659 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 2660 | |
| 2661 | return read_memory_integer (addr, len, byte_order); |
| 2662 | } |
| 2663 | |
| 2664 | ULONGEST |
| 2665 | get_frame_memory_unsigned (struct frame_info *this_frame, CORE_ADDR addr, |
| 2666 | int len) |
| 2667 | { |
| 2668 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
| 2669 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 2670 | |
| 2671 | return read_memory_unsigned_integer (addr, len, byte_order); |
| 2672 | } |
| 2673 | |
| 2674 | int |
| 2675 | safe_frame_unwind_memory (struct frame_info *this_frame, |
| 2676 | CORE_ADDR addr, gdb_byte *buf, int len) |
| 2677 | { |
| 2678 | /* NOTE: target_read_memory returns zero on success! */ |
| 2679 | return !target_read_memory (addr, buf, len); |
| 2680 | } |
| 2681 | |
| 2682 | /* Architecture methods. */ |
| 2683 | |
| 2684 | struct gdbarch * |
| 2685 | get_frame_arch (struct frame_info *this_frame) |
| 2686 | { |
| 2687 | return frame_unwind_arch (this_frame->next); |
| 2688 | } |
| 2689 | |
| 2690 | struct gdbarch * |
| 2691 | frame_unwind_arch (struct frame_info *next_frame) |
| 2692 | { |
| 2693 | if (!next_frame->prev_arch.p) |
| 2694 | { |
| 2695 | struct gdbarch *arch; |
| 2696 | |
| 2697 | if (next_frame->unwind == NULL) |
| 2698 | frame_unwind_find_by_frame (next_frame, &next_frame->prologue_cache); |
| 2699 | |
| 2700 | if (next_frame->unwind->prev_arch != NULL) |
| 2701 | arch = next_frame->unwind->prev_arch (next_frame, |
| 2702 | &next_frame->prologue_cache); |
| 2703 | else |
| 2704 | arch = get_frame_arch (next_frame); |
| 2705 | |
| 2706 | next_frame->prev_arch.arch = arch; |
| 2707 | next_frame->prev_arch.p = 1; |
| 2708 | if (frame_debug) |
| 2709 | fprintf_unfiltered (gdb_stdlog, |
| 2710 | "{ frame_unwind_arch (next_frame=%d) -> %s }\n", |
| 2711 | next_frame->level, |
| 2712 | gdbarch_bfd_arch_info (arch)->printable_name); |
| 2713 | } |
| 2714 | |
| 2715 | return next_frame->prev_arch.arch; |
| 2716 | } |
| 2717 | |
| 2718 | struct gdbarch * |
| 2719 | frame_unwind_caller_arch (struct frame_info *next_frame) |
| 2720 | { |
| 2721 | next_frame = skip_artificial_frames (next_frame); |
| 2722 | |
| 2723 | /* We must have a non-artificial frame. The caller is supposed to check |
| 2724 | the result of frame_unwind_caller_id (), which returns NULL_FRAME_ID |
| 2725 | in this case. */ |
| 2726 | gdb_assert (next_frame != NULL); |
| 2727 | |
| 2728 | return frame_unwind_arch (next_frame); |
| 2729 | } |
| 2730 | |
| 2731 | /* Gets the language of FRAME. */ |
| 2732 | |
| 2733 | enum language |
| 2734 | get_frame_language (struct frame_info *frame) |
| 2735 | { |
| 2736 | CORE_ADDR pc = 0; |
| 2737 | int pc_p = 0; |
| 2738 | |
| 2739 | gdb_assert (frame!= NULL); |
| 2740 | |
| 2741 | /* We determine the current frame language by looking up its |
| 2742 | associated symtab. To retrieve this symtab, we use the frame |
| 2743 | PC. However we cannot use the frame PC as is, because it |
| 2744 | usually points to the instruction following the "call", which |
| 2745 | is sometimes the first instruction of another function. So |
| 2746 | we rely on get_frame_address_in_block(), it provides us with |
| 2747 | a PC that is guaranteed to be inside the frame's code |
| 2748 | block. */ |
| 2749 | |
| 2750 | try |
| 2751 | { |
| 2752 | pc = get_frame_address_in_block (frame); |
| 2753 | pc_p = 1; |
| 2754 | } |
| 2755 | catch (const gdb_exception_error &ex) |
| 2756 | { |
| 2757 | if (ex.error != NOT_AVAILABLE_ERROR) |
| 2758 | throw; |
| 2759 | } |
| 2760 | |
| 2761 | if (pc_p) |
| 2762 | { |
| 2763 | struct compunit_symtab *cust = find_pc_compunit_symtab (pc); |
| 2764 | |
| 2765 | if (cust != NULL) |
| 2766 | return compunit_language (cust); |
| 2767 | } |
| 2768 | |
| 2769 | return language_unknown; |
| 2770 | } |
| 2771 | |
| 2772 | /* Stack pointer methods. */ |
| 2773 | |
| 2774 | CORE_ADDR |
| 2775 | get_frame_sp (struct frame_info *this_frame) |
| 2776 | { |
| 2777 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
| 2778 | |
| 2779 | /* NOTE drow/2008-06-28: gdbarch_unwind_sp could be converted to |
| 2780 | operate on THIS_FRAME now. */ |
| 2781 | return gdbarch_unwind_sp (gdbarch, this_frame->next); |
| 2782 | } |
| 2783 | |
| 2784 | /* Return the reason why we can't unwind past FRAME. */ |
| 2785 | |
| 2786 | enum unwind_stop_reason |
| 2787 | get_frame_unwind_stop_reason (struct frame_info *frame) |
| 2788 | { |
| 2789 | /* Fill-in STOP_REASON. */ |
| 2790 | get_prev_frame_always (frame); |
| 2791 | gdb_assert (frame->prev_p); |
| 2792 | |
| 2793 | return frame->stop_reason; |
| 2794 | } |
| 2795 | |
| 2796 | /* Return a string explaining REASON. */ |
| 2797 | |
| 2798 | const char * |
| 2799 | unwind_stop_reason_to_string (enum unwind_stop_reason reason) |
| 2800 | { |
| 2801 | switch (reason) |
| 2802 | { |
| 2803 | #define SET(name, description) \ |
| 2804 | case name: return _(description); |
| 2805 | #include "unwind_stop_reasons.def" |
| 2806 | #undef SET |
| 2807 | |
| 2808 | default: |
| 2809 | internal_error (__FILE__, __LINE__, |
| 2810 | "Invalid frame stop reason"); |
| 2811 | } |
| 2812 | } |
| 2813 | |
| 2814 | const char * |
| 2815 | frame_stop_reason_string (struct frame_info *fi) |
| 2816 | { |
| 2817 | gdb_assert (fi->prev_p); |
| 2818 | gdb_assert (fi->prev == NULL); |
| 2819 | |
| 2820 | /* Return the specific string if we have one. */ |
| 2821 | if (fi->stop_string != NULL) |
| 2822 | return fi->stop_string; |
| 2823 | |
| 2824 | /* Return the generic string if we have nothing better. */ |
| 2825 | return unwind_stop_reason_to_string (fi->stop_reason); |
| 2826 | } |
| 2827 | |
| 2828 | /* Return the enum symbol name of REASON as a string, to use in debug |
| 2829 | output. */ |
| 2830 | |
| 2831 | static const char * |
| 2832 | frame_stop_reason_symbol_string (enum unwind_stop_reason reason) |
| 2833 | { |
| 2834 | switch (reason) |
| 2835 | { |
| 2836 | #define SET(name, description) \ |
| 2837 | case name: return #name; |
| 2838 | #include "unwind_stop_reasons.def" |
| 2839 | #undef SET |
| 2840 | |
| 2841 | default: |
| 2842 | internal_error (__FILE__, __LINE__, |
| 2843 | "Invalid frame stop reason"); |
| 2844 | } |
| 2845 | } |
| 2846 | |
| 2847 | /* Clean up after a failed (wrong unwinder) attempt to unwind past |
| 2848 | FRAME. */ |
| 2849 | |
| 2850 | void |
| 2851 | frame_cleanup_after_sniffer (struct frame_info *frame) |
| 2852 | { |
| 2853 | /* The sniffer should not allocate a prologue cache if it did not |
| 2854 | match this frame. */ |
| 2855 | gdb_assert (frame->prologue_cache == NULL); |
| 2856 | |
| 2857 | /* No sniffer should extend the frame chain; sniff based on what is |
| 2858 | already certain. */ |
| 2859 | gdb_assert (!frame->prev_p); |
| 2860 | |
| 2861 | /* The sniffer should not check the frame's ID; that's circular. */ |
| 2862 | gdb_assert (!frame->this_id.p); |
| 2863 | |
| 2864 | /* Clear cached fields dependent on the unwinder. |
| 2865 | |
| 2866 | The previous PC is independent of the unwinder, but the previous |
| 2867 | function is not (see get_frame_address_in_block). */ |
| 2868 | frame->prev_func.p = 0; |
| 2869 | frame->prev_func.addr = 0; |
| 2870 | |
| 2871 | /* Discard the unwinder last, so that we can easily find it if an assertion |
| 2872 | in this function triggers. */ |
| 2873 | frame->unwind = NULL; |
| 2874 | } |
| 2875 | |
| 2876 | /* Set FRAME's unwinder temporarily, so that we can call a sniffer. |
| 2877 | If sniffing fails, the caller should be sure to call |
| 2878 | frame_cleanup_after_sniffer. */ |
| 2879 | |
| 2880 | void |
| 2881 | frame_prepare_for_sniffer (struct frame_info *frame, |
| 2882 | const struct frame_unwind *unwind) |
| 2883 | { |
| 2884 | gdb_assert (frame->unwind == NULL); |
| 2885 | frame->unwind = unwind; |
| 2886 | } |
| 2887 | |
| 2888 | static struct cmd_list_element *set_backtrace_cmdlist; |
| 2889 | static struct cmd_list_element *show_backtrace_cmdlist; |
| 2890 | |
| 2891 | static void |
| 2892 | set_backtrace_cmd (const char *args, int from_tty) |
| 2893 | { |
| 2894 | help_list (set_backtrace_cmdlist, "set backtrace ", all_commands, |
| 2895 | gdb_stdout); |
| 2896 | } |
| 2897 | |
| 2898 | static void |
| 2899 | show_backtrace_cmd (const char *args, int from_tty) |
| 2900 | { |
| 2901 | cmd_show_list (show_backtrace_cmdlist, from_tty, ""); |
| 2902 | } |
| 2903 | |
| 2904 | /* Definition of the "set backtrace" settings that are exposed as |
| 2905 | "backtrace" command options. */ |
| 2906 | |
| 2907 | using boolean_option_def |
| 2908 | = gdb::option::boolean_option_def<set_backtrace_options>; |
| 2909 | using uinteger_option_def |
| 2910 | = gdb::option::uinteger_option_def<set_backtrace_options>; |
| 2911 | |
| 2912 | const gdb::option::option_def set_backtrace_option_defs[] = { |
| 2913 | |
| 2914 | boolean_option_def { |
| 2915 | "past-main", |
| 2916 | [] (set_backtrace_options *opt) { return &opt->backtrace_past_main; }, |
| 2917 | show_backtrace_past_main, /* show_cmd_cb */ |
| 2918 | N_("Set whether backtraces should continue past \"main\"."), |
| 2919 | N_("Show whether backtraces should continue past \"main\"."), |
| 2920 | N_("Normally the caller of \"main\" is not of interest, so GDB will terminate\n\ |
| 2921 | the backtrace at \"main\". Set this if you need to see the rest\n\ |
| 2922 | of the stack trace."), |
| 2923 | }, |
| 2924 | |
| 2925 | boolean_option_def { |
| 2926 | "past-entry", |
| 2927 | [] (set_backtrace_options *opt) { return &opt->backtrace_past_entry; }, |
| 2928 | show_backtrace_past_entry, /* show_cmd_cb */ |
| 2929 | N_("Set whether backtraces should continue past the entry point of a program."), |
| 2930 | N_("Show whether backtraces should continue past the entry point of a program."), |
| 2931 | N_("Normally there are no callers beyond the entry point of a program, so GDB\n\ |
| 2932 | will terminate the backtrace there. Set this if you need to see\n\ |
| 2933 | the rest of the stack trace."), |
| 2934 | }, |
| 2935 | }; |
| 2936 | |
| 2937 | void |
| 2938 | _initialize_frame (void) |
| 2939 | { |
| 2940 | obstack_init (&frame_cache_obstack); |
| 2941 | |
| 2942 | frame_stash_create (); |
| 2943 | |
| 2944 | gdb::observers::target_changed.attach (frame_observer_target_changed); |
| 2945 | |
| 2946 | add_prefix_cmd ("backtrace", class_maintenance, set_backtrace_cmd, _("\ |
| 2947 | Set backtrace specific variables.\n\ |
| 2948 | Configure backtrace variables such as the backtrace limit"), |
| 2949 | &set_backtrace_cmdlist, "set backtrace ", |
| 2950 | 0/*allow-unknown*/, &setlist); |
| 2951 | add_prefix_cmd ("backtrace", class_maintenance, show_backtrace_cmd, _("\ |
| 2952 | Show backtrace specific variables\n\ |
| 2953 | Show backtrace variables such as the backtrace limit"), |
| 2954 | &show_backtrace_cmdlist, "show backtrace ", |
| 2955 | 0/*allow-unknown*/, &showlist); |
| 2956 | |
| 2957 | add_setshow_uinteger_cmd ("limit", class_obscure, |
| 2958 | &user_set_backtrace_options.backtrace_limit, _("\ |
| 2959 | Set an upper bound on the number of backtrace levels."), _("\ |
| 2960 | Show the upper bound on the number of backtrace levels."), _("\ |
| 2961 | No more than the specified number of frames can be displayed or examined.\n\ |
| 2962 | Literal \"unlimited\" or zero means no limit."), |
| 2963 | NULL, |
| 2964 | show_backtrace_limit, |
| 2965 | &set_backtrace_cmdlist, |
| 2966 | &show_backtrace_cmdlist); |
| 2967 | |
| 2968 | gdb::option::add_setshow_cmds_for_options |
| 2969 | (class_stack, &user_set_backtrace_options, |
| 2970 | set_backtrace_option_defs, &set_backtrace_cmdlist, &show_backtrace_cmdlist); |
| 2971 | |
| 2972 | /* Debug this files internals. */ |
| 2973 | add_setshow_zuinteger_cmd ("frame", class_maintenance, &frame_debug, _("\ |
| 2974 | Set frame debugging."), _("\ |
| 2975 | Show frame debugging."), _("\ |
| 2976 | When non-zero, frame specific internal debugging is enabled."), |
| 2977 | NULL, |
| 2978 | show_frame_debug, |
| 2979 | &setdebuglist, &showdebuglist); |
| 2980 | } |